Coco Gauff should be the clear favourite when she opens her U.S. Open campaign against Zeynep Sonmez on Tuesday night, but the match does not look like a mismatch on paper. The betting line of +6.5 games suggests Sonmez can make this more competitive than a routine first-round win for the 2023 champion.
That matters because Gauff arrives with strong recent results. She won the Cincinnati Open in 2025, reached the semifinals at Wimbledon and also made the semifinals at the National Bank Open in Canada. She is also chasing a second U.S. Open title after winning the event in 2023.
Why Sonmez is a credible underdog
Sonmez is not being asked to win the tournament, only to stay in the match long enough to cover a sizeable spread. That is where the Sönmez Tennis case becomes interesting for bettors, because she has already shown she can handle higher-level opposition, including wins over top-50 players.
Her 2025 season has also given her some momentum. She reached the third round at Wimbledon and the third round at the Australian Open, which is a sign of a player taking gradual steps forward at Grand Slam level.
Gauff’s standard is still the benchmark
Gauff’s record at the U.S. Open remains the standard Sonmez must try to live with. The American won the title in 2023 and reached the fourth round in 2024, so the expectation is not only that she advances, but that she does so in control.
Even so, first rounds at majors can be awkward when the favourite is still adjusting to the tournament pressure and the underdog has little to lose. Sonmez’s best U.S. Open result came in 2024 when she reached the second round, and she now has a chance to push that a step further.
What the game spread suggests
The +6.5 Games number tells you how this matchup is being framed. It does not suggest Sonmez is expected to pull off the upset, but it does point to a contest where she can do enough to stay within range if she serves well and avoids a run of loose games.
For Gauff, the task is straightforward: use her level, experience and recent form to settle the match early. For Sonmez, the challenge is to stay composed and make the favourite earn every break.
That is why this first-round tie is more than a routine opening match. Gauff should still be expected to progress, but Sönmez Tennis has a clear betting angle: Sonmez looks capable of keeping the score close enough to matter.
