H2H data updated: 2026-09-13 00:00 UTC
Monica Niculescu holds a 2–0 lead over Katie Obrien in their WTA head-to-head. Across 2 main-draw meetings, Monica Niculescu leads 1–0 on clay and 1–0 on hard courts. Most recently, Monica Niculescu won the 2009 Prague round of 32 6-3 6-2.
Want to explore more matchups? Advanced rivalry search lets you browse current and historical rivalries, unbeaten records, or every matchup for a player.
| Player | Score | Player | Match Data | Date | Round | Tournament | Category | Surface |
|---|---|---|---|---|---|---|---|---|
| Monica Niculescu | 6-3 6-2 | Katie Obrien | Match data | Jul 16, 2009* | R32 | Prague | International → modern equivalent WTA 250 | Clay |
| Monica Niculescu | 6-4 6-4 | Katie Obrien | Match data | Jan 21, 2009* | R128 | Australian Open | Grand Slam | Hard |
Estimated match date where the exact historical date is unavailable. Arrows show an edition's recorded category and documented modern equivalent; unresolved editions keep their recorded category. Asterisked totals include editions mapped from documented historical predecessor categories. Mapping details.
| Player | Current | Peak | Pts | Elo | W | L | Win % | GS | 1000 including documented historical predecessor categories | Finals | 500 including documented historical predecessor categories | 250 including documented historical predecessor categories | Titles |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Monica Niculescu | #958 | #28 | 1,960 | 1,779 | 179 | 214 | 45.5% | 0 | 0 | 0 | 0 | 3 | 3 |
| Katie Obrien | #782 | #84 | 769 | 1,514 | 9 | 34 | 20.9% | 0 | 0 | 0 | 0 | 0 | 0 |
Seasons are aligned by the age each player spent most of that calendar year. GS and Titles are cumulative career totals through that season.
| Monica Niculescu | Katie Obrien | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Yr | W-L | Win % | Rank | Elo | GS | Titles | Yr | W-L | Win % | Rank | Elo | GS | Titles |
| 2007 | 0–1 | 0.0% | #152 | 1,490 | 0 | 0 | 2004 | 0–1 | 0.0% | #387 | 1,492 | 0 | 0 |
| 2008 | 8–15 | 34.8% | #48 | 1,543 | 0 | 0 | 2005 | 0–1 | 0.0% | #267 | 1,492 | 0 | 0 |
| 2009 | 10–22 | 31.2% | #103 | 1,522 | 0 | 0 | 2006 | 0–3 | 0.0% | #187 | 1,461 | 0 | 0 |
| 2010 | 6–9 | 40.0% | #82 | 1,574 | 0 | 0 | 2007 | 4–3 | 57.1% | #127 | 1,501 | 0 | 0 |
| 2011 | 21–15 | 58.3% | #30 | 1,757 | 0 | 0 | 2008 | 2–8 | 20.0% | #159 | 1,450 | 0 | 0 |
| 2012 | 15–23 | 39.5% | #58 | 1,639 | 0 | 0 | 2009 | 1–9 | 10.0% | #88 | 1,390 | 0 | 0 |
| 2013 | 22–21 | 51.2% | #59 | 1,635 | 0 | 1 | 2010 | 2–8 | 20.0% | #179 | 1,370 | 0 | 0 |
| 2014 | 22–19 | 53.7% | #46 | 1,688 | 0 | 2 | 2011 | 0–1 | 0.0% | #357 | 1,365 | 0 | 0 |
| 2015 | 20–21 | 48.8% | #39 | 1,676 | 0 | 2 | — | — | — | — | — | — | — |
| 2016 | 26–19 | 57.8% | #38 | 1,758 | 0 | 3 | — | — | — | — | — | — | — |
| 2017 | 12–19 | 38.7% | #77 | 1,622 | 0 | 3 | — | — | — | — | — | — | — |
| 2018 | 9–15 | 37.5% | #99 | 1,591 | 0 | 3 | — | — | — | — | — | — | — |
| 2019 | 8–10 | 44.4% | #118 | 1,638 | 0 | 3 | — | — | — | — | — | — | — |
| 2020 | 0–2 | 0.0% | #144 | 1,586 | 0 | 3 | — | — | — | — | — | — | — |
| 2021 | 0–3 | 0.0% | #274 | 1,519 | 0 | 3 | — | — | — | — | — | — | — |
Rows are aligned in career order because complete birth data is unavailable. Results cover completed main-draw matches. Bold green marks the higher win percentage when both players have at least 5 matches on that surface at the aligned age.
| Monica Niculescu | Katie Obrien | ||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Yr | Hard | Clay | Grass | Carpet | Yr | Hard | Clay | Grass | Carpet | ||||||||||||||||||||||||
| W | L | M | Win % | W | L | M | Win % | W | L | M | Win % | W | L | M | Win % | W | L | M | Win % | W | L | M | Win % | W | L | M | Win % | W | L | M | Win % | ||
| 2007 | 0 | 1 | 1 | 0.0% | — | — | — | — | — | — | — | — | — | — | — | — | 2004 | — | — | — | — | — | — | — | — | 0 | 1 | 1 | 0.0% | — | — | — | — |
| 2008 | 6 | 10 | 16 | 37.5% | 1 | 3 | 4 | 25.0% | 1 | 2 | 3 | 33.3% | — | — | — | — | 2005 | — | — | — | — | — | — | — | — | 0 | 1 | 1 | 0.0% | — | — | — | — |
| 2009 | 6 | 13 | 19 | 31.6% | 3 | 6 | 9 | 33.3% | 0 | 2 | 2 | 0.0% | 1 | 1 | 2 | 50.0% | 2006 | — | — | — | — | — | — | — | — | 0 | 3 | 3 | 0.0% | — | — | — | — |
| 2010 | 4 | 7 | 11 | 36.4% | 1 | 1 | 2 | 50.0% | 1 | 1 | 2 | 50.0% | — | — | — | — | 2007 | 2 | 1 | 3 | 66.7% | — | — | — | — | 2 | 2 | 4 | 50.0% | — | — | — | — |
| 2011 | 17 | 9 | 26 | 65.4% | 3 | 4 | 7 | 42.9% | 1 | 2 | 3 | 33.3% | — | — | — | — | 2008 | 1 | 3 | 4 | 25.0% | 0 | 2 | 2 | 0.0% | 1 | 3 | 4 | 25.0% | — | — | — | — |
| 2012 | 12 | 15 | 27 | 44.4% | 1 | 5 | 6 | 16.7% | 1 | 2 | 3 | 33.3% | 1 | 1 | 2 | 50.0% | 2009 | 1 | 4 | 5 | 20.0% | 0 | 3 | 3 | 0.0% | 0 | 2 | 2 | 0.0% | — | — | — | — |
| 2013 | 20 | 14 | 34 | 58.8% | 2 | 4 | 6 | 33.3% | 0 | 2 | 2 | 0.0% | 0 | 1 | 1 | 0.0% | 2010 | 1 | 4 | 5 | 20.0% | 1 | 2 | 3 | 33.3% | 0 | 2 | 2 | 0.0% | — | — | — | — |
| 2014 | 18 | 14 | 32 | 56.3% | 4 | 4 | 8 | 50.0% | 0 | 1 | 1 | 0.0% | — | — | — | — | 2011 | — | — | — | — | — | — | — | — | 0 | 1 | 1 | 0.0% | — | — | — | — |
| 2015 | 10 | 14 | 24 | 41.7% | 3 | 3 | 6 | 50.0% | 7 | 4 | 11 | 63.6% | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| 2016 | 23 | 13 | 36 | 63.9% | 2 | 5 | 7 | 28.6% | 1 | 1 | 2 | 50.0% | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| 2017 | 11 | 13 | 24 | 45.8% | 0 | 4 | 4 | 0.0% | 1 | 2 | 3 | 33.3% | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| 2018 | 9 | 14 | 23 | 39.1% | — | — | — | — | 0 | 1 | 1 | 0.0% | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| 2019 | 7 | 8 | 15 | 46.7% | — | — | — | — | 1 | 2 | 3 | 33.3% | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| 2020 | 0 | 1 | 1 | 0.0% | 0 | 1 | 1 | 0.0% | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| 2021 | 0 | 2 | 2 | 0.0% | — | — | — | — | 0 | 1 | 1 | 0.0% | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Career | 143 | 148 | 291 | 49.1% | 20 | 40 | 60 | 33.3% | 14 | 23 | 37 | 37.8% | 2 | 3 | 5 | 40.0% | Career | 5 | 12 | 17 | 29.4% | 1 | 7 | 8 | 12.5% | 3 | 15 | 18 | 16.7% | — | — | — | — |
Rows are aligned in career order because complete birth data is unavailable. Detailed serve and return statistics available for 341/394 of Monica Niculescu's and 31/42 of Katie Obrien's main draw matches. Sample is shown as matches with detailed serve and return statistics / total main draw matches. Bold green marks the stronger value when both stat samples contain at least 5 matches; lower is better for DFs/M.
| Monica Niculescu | Katie Obrien | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Yr | Sample | Aces/M | DFs/M | 1st Sv% | 1st Pts% | 2nd Pts% | BP Saved% | BP Conv% | Svc Pts% | Ret Pts% | Yr | Sample | Aces/M | DFs/M | 1st Sv% | 1st Pts% | 2nd Pts% | BP Saved% | BP Conv% | Svc Pts% | Ret Pts% |
| 2007 | 1/1 | 0.0 | 4.0 | 57.4% | 45.2% | 34.8% | 25.0% | 100.0% | 40.7% | 30.8% | 2005 | 1/1 | 0.0 | 4.0 | 51.2% | 63.6% | 47.6% | 0.0% | — | 55.8% | 20.0% |
| 2008 | 19/23 | 1.3 | 1.9 | 72.5% | 54.5% | 38.0% | 41.9% | 45.0% | 49.9% | 43.0% | 2006 | 2/3 | 1.5 | 6.0 | 58.1% | 57.7% | 42.1% | 37.9% | 62.5% | 51.1% | 42.8% |
| 2009 | 30/32 | 1.0 | 1.4 | 71.6% | 55.9% | 46.3% | 44.0% | 48.4% | 52.8% | 43.8% | 2007 | 4/7 | 2.3 | 5.3 | 55.7% | 62.5% | 36.7% | 44.9% | 36.4% | 51.4% | 42.2% |
| 2010 | 12/15 | 0.3 | 1.0 | 73.4% | 53.0% | 39.4% | 47.7% | 45.0% | 49.3% | 43.9% | 2008 | 6/10 | 1.5 | 6.7 | 54.5% | 62.6% | 43.3% | 54.5% | 42.0% | 53.7% | 42.6% |
| 2011 | 29/36 | 0.7 | 1.5 | 74.9% | 55.3% | 46.1% | 44.2% | 60.9% | 52.3% | 48.8% | 2009 | 9/10 | 1.2 | 6.6 | 59.0% | 54.7% | 35.8% | 45.2% | 44.2% | 46.9% | 39.4% |
| 2012 | 33/38 | 1.3 | 1.1 | 67.1% | 58.0% | 47.7% | 51.8% | 46.0% | 54.3% | 43.3% | 2010 | 8/10 | 1.6 | 6.3 | 59.5% | 54.8% | 39.7% | 41.7% | 33.7% | 49.0% | 37.8% |
| 2013 | 37/43 | 0.8 | 1.5 | 74.6% | 59.2% | 45.9% | 47.0% | 52.2% | 55.3% | 49.4% | 2011 | 1/1 | 2.0 | 5.0 | 62.9% | 46.2% | 30.4% | 41.7% | 60.0% | 40.3% | 37.5% |
| 2014 | 34/41 | 1.2 | 3.1 | 70.2% | 60.8% | 41.3% | 50.8% | 59.1% | 55.0% | 51.0% | — | —/— | — | — | — | — | — | — | — | — | — |
| 2015 | 32/41 | 1.1 | 2.8 | 70.4% | 60.4% | 46.2% | 47.8% | 43.9% | 55.9% | 43.1% | — | —/— | — | — | — | — | — | — | — | — | — |
| 2016 | 41/46 | 1.3 | 1.9 | 71.6% | 57.0% | 43.8% | 43.2% | 51.4% | 53.4% | 50.0% | — | —/— | — | — | — | — | — | — | — | — | — |
| 2017 | 27/31 | 0.4 | 1.2 | 82.8% | 52.1% | 47.0% | 51.7% | 49.9% | 51.2% | 44.9% | — | —/— | — | — | — | — | — | — | — | — | — |
| 2018 | 23/24 | 0.3 | 1.5 | 77.6% | 55.6% | 46.3% | 46.4% | 51.8% | 53.0% | 47.4% | — | —/— | — | — | — | — | — | — | — | — | — |
| 2019 | 18/18 | 0.4 | 1.5 | 79.1% | 56.5% | 45.6% | 37.0% | 46.4% | 54.6% | 46.2% | — | —/— | — | — | — | — | — | — | — | — | — |
| 2020 | 2/2 | 1.0 | 1.5 | 79.6% | 49.7% | 35.3% | 49.4% | 42.2% | 46.7% | 40.2% | — | —/— | — | — | — | — | — | — | — | — | — |
| 2021 | 3/3 | 0.3 | 1.3 | 74.9% | 47.5% | 49.1% | 46.0% | 50.0% | 46.5% | 36.7% | — | —/— | — | — | — | — | — | — | — | — | — |
| Career | 341/394 | 0.9 | 1.8 | 73.4% | 56.9% | 44.8% | 46.4% | 50.7% | 53.3% | 46.5% | Career | 31/43 | 1.5 | 6.2 | 57.6% | 57.5% | 39.0% | 44.0% | 40.3% | 49.7% | 39.5% |
Rows are aligned in career order because complete birth data is unavailable. Metrics use eligible main-draw results; point statistics use matches with detailed data. Bold green marks the stronger value when both underlying samples are sufficient. Lower is better for Schedule because a negative value means a tougher schedule. Career Schedule is normalized per 100 matches.
| Monica Niculescu | Katie Obrien | ||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Yr | Elo | P+ | Serve+ | Return+ | PD | TPW% | Hard Elo | Clay Elo | Grass Elo | Set Win % | Set Margin | Dec. Set | Tiebreak | Pressure+ | Schedule | Yr | Elo | P+ | Serve+ | Return+ | PD | TPW% | Hard Elo | Clay Elo | Grass Elo | Set Win % | Set Margin | Dec. Set | Tiebreak | Pressure+ | Schedule |
| 2007 | 1491 | 98.2 | -0.35 | +1.13 | 0.519 | 36.6% | — | — | — | 0.0% | -4.50 | — | — | — | +0.05 | 2004 | 1492 | 98.4 | — | — | — | — | — | — | — | 0.0% | -2.00 | — | — | — | -0.06 |
| 2008 | 1543 | 120.1 | -2.90 | -0.19 | 0.859 | 46.3% | +10 | -13 | +47 | 34.6% | -1.12 | 4–6 (40%) | 1–2 (33%) | 99.8 | +0.05 | 2005 | 1492 | 103.3 | +4.63 | +2.47 | 0.453 | 37.5% | — | — | — | 0.0% | -3.50 | — | — | — | -0.29 |
| 2009 | 1523 | 112.7 | -2.66 | -0.26 | 0.928 | 48.0% | +26 | -22 | — | 34.7% | -1.10 | 3–7 (30%) | 2–1 (67%) | — | +0.79 | 2006 | 1462 | 94.0 | -0.38 | +0.43 | 0.876 | 47.0% | — | — | +15 | 25.0% | -1.50 | 0–2 | 0–1 | — | +0.02 |
| 2010 | 1574 | 117.8 | -2.83 | +0.34 | 0.866 | 46.8% | -1 | — | — | 41.7% | -0.81 | 3–3 (50%) | 1–2 (33%) | 101.0 | -0.32 | 2007 | 1502 | 98.4 | -1.08 | -1.93 | 0.868 | 46.8% | +35 | — | +18 | 53.3% | -0.33 | 1–0 | 1–0 | — | +0.89 |
| 2011 | 1758 | 133.3 | -2.06 | +3.84 | 1.021 | 50.5% | -10 | -238 | -215 | 53.8% | +0.41 | 7–3 (70%) | 3–5 (38%) | 103.5 | +0.37 | 2008 | 1451 | 98.3 | -1.41 | -1.77 | 0.920 | 48.4% | +67 | — | +20 | 30.8% | -1.19 | 2–4 (33%) | 3–0 (100%) | — | +0.44 |
| 2012 | 1640 | 125.0 | -1.30 | -0.32 | 0.949 | 48.8% | +48 | -164 | -85 | 42.4% | -0.47 | 3–8 (27%) | 6–1 (86%) | 96.9 | +0.44 | 2009 | 1391 | 89.7 | -5.01 | -2.96 | 0.742 | 43.3% | +96 | +66 | — | 21.7% | -2.04 | 0–3 (0%) | 0–1 | — | +0.39 |
| 2013 | 1635 | 132.6 | -0.55 | +4.14 | 1.104 | 52.3% | +66 | -181 | — | 52.1% | +0.24 | 6–8 (43%) | 4–2 (67%) | 97.6 | -0.53 | 2010 | 1371 | 97.5 | -2.84 | -3.79 | 0.741 | 43.8% | +103 | +65 | — | 29.2% | -1.67 | 1–3 (25%) | 1–0 | — | +0.42 |
| 2014 | 1688 | 140.2 | -1.17 | +5.03 | 1.133 | 53.0% | +7 | -148 | — | 57.1% | +1.03 | 8–12 (40%) | 2–6 (25%) | 93.9 | -0.85 | 2011 | 1366 | 99.1 | -2.49 | -4.08 | 0.628 | 39.1% | — | — | — | 0.0% | -4.00 | — | — | — | -0.01 |
| 2015 | 1677 | 131.5 | -1.57 | +1.81 | 0.978 | 49.6% | -20 | -106 | -62 | 50.0% | +0.03 | 10–10 (50%) | 4–0 (100%) | 105.1 | -0.95 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| 2016 | 1759 | 135.4 | -1.87 | +5.53 | 1.073 | 51.7% | +23 | -229 | — | 56.0% | +0.42 | 8–6 (57%) | 1–4 (20%) | 100.6 | +0.22 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| 2017 | 1622 | 118.4 | -3.66 | +1.26 | 0.920 | 48.1% | +24 | -137 | -27 | 40.9% | -0.64 | 5–5 (50%) | 3–2 (60%) | 100.1 | +0.21 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| 2018 | 1591 | 133.1 | -2.27 | +2.61 | 1.010 | 50.2% | +6 | — | — | 39.6% | -0.48 | 3–5 (38%) | 1–2 (33%) | — | -0.38 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| 2019 | 1638 | 129.0 | -1.03 | +1.89 | 1.019 | 50.3% | +11 | — | -43 | 46.2% | -0.05 | 3–4 (43%) | 2–5 (29%) | 98.8 | -0.23 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| 2020 | 1587 | 99.7 | -1.05 | +1.06 | 0.754 | 43.7% | — | — | — | 33.3% | -2.34 | 0–2 | — | — | -0.11 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| 2021 | 1519 | 98.6 | -2.42 | -0.40 | 0.685 | 41.9% | — | — | — | 0.0% | -3.17 | — | — | — | -0.37 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| 2023 | 1531 | 101.7 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Career | 1780 | 134.0 | -1.87 | +2.44 | 0.996 | 49.9% | +19 | -140 | -64 | 46.8% | -0.13 | 63–79 (44%) | 30–32 (48%) | 97.9 | -0.41 | Career | 1514 | 93.8 | -2.56 | -2.45 | 0.785 | 44.8% | +80 | +66 | +18 | 29.4% | -1.51 | 4–12 (25%) | 5–2 (71%) | 95.3 | +4.19 |
Each player's five most-played main-draw opponents. The current matchup is highlighted when it appears in a player's top five.
| Opponent | W | L | M | Last Played | H2H |
|---|---|---|---|---|---|
| Caroline Wozniacki | 1 | 9 | 10 | Mar 24, 2019 | H2H |
| Jelena Jankovic | 3 | 5 | 8 | Jan 11, 2017 | H2H |
| Kirsten Flipkens | 3 | 4 | 7 | Feb 22, 2018 | H2H |
| Samantha Stosur | 0 | 7 | 7 | Oct 5, 2015 | H2H |
| Sorana Cirstea | 2 | 4 | 6 | Aug 8, 2018 | H2H |
| Opponent | W | L | M | Last Played | H2H |
|---|---|---|---|---|---|
| Alla Kudryavtseva | 1 | 1 | 2 | Sep 17, 2009 | H2H |
| Monica Niculescu | 0 | 2 | 2 | Jul 16, 2009 | H2H |
| Olga Govortsova | 0 | 2 | 2 | May 26, 2009 | H2H |
| Kimiko Date | 0 | 1 | 1 | Jun 22, 2011 | H2H |
| Ekaterina Ivanova | 0 | 1 | 1 | Sep 23, 2010 | H2H |