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Sports · US Open 2026 · Women's Singles · Round of 64
Naomi Osaka vs Katerina Siniakova — 6-2 5-7 6-1
 Naomi Osaka✓ | 6 | 5 | 6 |
 Katerina Siniakova | 2 | 7 | 1 |
Final · Thursday, September 3, 2026 · Round of 64
Result
Naomi Osaka opened the day session on Arthur Ashe in a white walk-on gown trained with press clippings of her own career, won the first set in twenty-nine minutes, and then lost her serve three times in a row. The opener turned on a break to love and a game in which Katerina Siniakova served three double faults; Osaka then led 4-2 and 5-3 in the second and won only one more game in it, Siniakova closing it out with backhands down the line. She is the world No. 1 in doubles and had gone four years without a US Open singles main-draw win before this week. Osaka broke to start the third on a ball that clipped the net cord and dropped on the sideline, apologised across the net for it, broke again with a running forehand volley for 5-1, and finished on a service winner: eleven aces to three, six breaks from ten chances against three from eight. It is her eighth US Open third round, and her eleventh Grand Slam match win of a season that has already brought first quarter-finals at Roland Garros and Wimbledon.
Naomi OsakaRows the source hadn’t published are left off rather than guessed.
At this Stage
The Round of 64 halves the draw again: 32 women's matches across Wednesday and Thursday, every one of them between players who have already won here this week. The seeds who came through the opening round now meet opponents with form behind them rather than a ranking.
Round of 128
Round of 64
What we know now
Court: Arthur Ashe Stadium
Match length: 2:02
Watch: ESPN · ESPN2 · ABC · ESPN app
What I said beforehand
The preview, frozen before the first serve. Clearly dated, never rewritten — that's the deal that makes the pick worth anything.
Osaka leads this 2-1 and won the last one 6-3 6-2, but Monday's evidence cuts both ways. She needed two tiebreaks and two hours two minutes to beat the world No. 101 Anastasia Zakharova, was broken serving for the first set, and was a point from 5-6 down in the second before winning four straight and taking the breaker 7-3. Ten of her eleven aces came in that second set, which is the version of her that wins this tournament. Siniakova beat Elisabetta Cocciaretto 6-3 6-2 in far less time and far less trouble. She is one of the great doubles players of the era and a far better mover than her singles ranking of 42 suggests, but her best US Open singles run is a third round eight years ago, and the two-time champion here has cleared the first round nine times in ten. The case for the upset is a first serve that landed only half the time on Monday.
The case for Naomi Osaka
70% to winTwo US Open titles, a semi-final last year, and a 2-1 record against Siniakova including a straight-sets win at Wimbledon last summer. Osaka has ten Grand Slam match wins already in 2026 — her first double-figure major season since 2019 — and eleven aces in a first-round match is a serve doing exactly what it needs to. Siniakova has been past the second round here once in her career.
The case for Katerina Siniakova
30% to winSiniakova took ninety minutes less than Osaka to reach this round and did not face a tiebreak. She has beaten Osaka before, on clay at Roland Garros in 2019, and her return game is the part of this match Osaka's numbers are most exposed to: 51% first serves in on Monday, and four breaks conceded from seven chances. A player who has won ten Grand Slam doubles titles reads a serve better than most.
Both cases written 2026-09-01, before the first ball — frozen into the record exactly as written, whatever the result. The percentages are mine — opinions with a percent sign on. They add to 100 because tennis has no draw to hide the rounding in.
My locked pick: Naomi Osaka to advance ✓ RIGHT
“A two-time champion who leads the head-to-head, against a much sharper first round from the underdog and a first serve that landed half the time.”
Locked 2026-09-01 09:45 UTC — rendered verbatim from the pick ledger; never a fresher, hedged version
Tale of the tape
Naomi OsakaKaterina SiniakovaPlayer vitals: US Open official player feed (usopen.org) and Tennis Abstract career match logs · as of 2026-09-02.
Career head-to-head: Tennis Abstract career match logs (tour-level) · as of 2026-09-01.
Storylines
- Osaka beat Anastasia Zakharova 7-6(6) 7-6(3) in a match that finished around 12:30 a.m.; ten of her eleven aces came in the second set.
- Siniakova beat Elisabetta Cocciaretto 6-3 6-2.
- Osaka leads the head-to-head 2-1 and won the most recent meeting 6-3 6-2 at Wimbledon in 2025.
- Osaka has won this tournament twice, in 2018 and 2020, and reached the semi-finals last year; Siniakova's best US Open singles run is the third round in 2018.
- Osaka landed only 51% of her first serves on Monday and was broken four times.
Head to head
Three meetings, Osaka 2-1: she won at Doha in 2018 on a hard court and at Wimbledon in June 2025 on grass, Siniakova at Roland Garros in 2019 on clay. Their only hard-court meeting was the Doha match.
Source: Tennis Abstract career match logs (tour-level) · as of 2026-09-01.
Court & schedule: Arthur Ashe Stadium, Thursday 3 September. The US Open posts each day's order of play the evening before; this one is on the board. (Official US Open order of play, as of 2026-09-02)
Weather: Sunday — the men's final, and the last match of the fortnight — is 78°F with showers and thunderstorms 95% likely, the wettest day of the two weeks and the one day that cannot be pushed back. Ashe closes its roof and plays on. It clears overnight: 20% Sunday night, 20% Monday, then dry and sunny from Tuesday. (National Weather Service New York forecast, as of 2026-09-13)
Venue: USTA Billie Jean King National Tennis Center, Flushing Meadows, New York — hard.