Osaka survives US Open second round: The win hiding big questions about her serve

Round 2 of US Open 2026, Arthur Ashe Stadium was still packed when Naomi Osaka stepped out to face Katerina Siniakova. The match lasted 2 hours 41 minutes, ending 6-3, 6-7(5), 6-1 in favor of the Japanese player. But if we only look at the scoreline, fans will miss the real story unfolding inside Osaka's game. Osaka started like a machine. In her first seven service games, she did not give Siniakova a single break point opportunity. The powerful forehands were operating perfectly, footwork was sharp, and the first set closed convincingly at 6-3. Then everything suddenly collapsed. The second set witnessed a completely different Osaka. Leading 5-3, she lost three consecutive service games, including the decisive one in the tiebreak. Siniakova, though lacking superior power, exploited her opponent's rhythm disruption to the fullest. This was the second consecutive time at this tournament that Osaka lost focus — in round 1, she allowed Zakharova, the world No. 101, to break her serve four times. What's noteworthy is her ability to self-correct. In the deciding set, Osaka returned with a dominant 6-1, as if the second set had never existed. This reset demonstrates that the mentality of a 4-time Grand Slam champion remains intact. But the big question is: will this ability be enough against sustained pressure from opponents far stronger than Siniakova? Looking at the full 2026 season picture, Osaka has made remarkable progress in surface diversity. Reaching the third round of the Australian Open, fourth round of Roland Garros, and quarterfinals of Wimbledon — the first time since 2026 she has gone deep at all four majors in a single season. Reaching the US Open third round for the 8th time in 10 main draw appearances is clear proof that hard courts remain her home. Fans look at the victory, I look at the breathing rhythm of the match. And Osaka's rhythm is showing worrying irregularities. Osaka's next opponent is Elise Mertens, the No. 20 seed, a Belgian player with a solid and consistent game. Mertens has reached the US Open quarterfinals twice (2026, 2026) and has made the third round of a major 29 times in 39 attempts — a model of consistency. But the head-to-head record heavily favors Osaka: 6-3 career, and in two meetings in 2026, Osaka won both while dropping only 9 games total. The truth few mention: the comparison with 2026 could be a media trap. That year Osaka won the US Open, while this year she has only reached the later rounds — third round, fourth round, quarterfinals — not title-winning peaks. Looking at the numbers, people easily mistake this for a return to peak form. But in reality, current Osaka is a solid top-16 seed, not a top title contender. Osaka's biggest tactical blind spot lies in her serve inconsistency. Seven perfect service games followed by three consecutive service breaks — this pattern has repeated in both rounds. Against an elite returner in the top 8, this pattern would almost certainly be punished. I am old, but the pulse of the ball never grows old. And the ball is telling us that Osaka needs to thoroughly resolve her mid-match concentration issues if she wants to go deeper than the third round this year. The match against Mertens will be the first real test. An expected victory would confirm her seed status. A defeat would open big questions about her ability to compete at the highest level. But regardless of the outcome, what I care most about is: can Osaka maintain a consistent service rhythm throughout the entire match, or will she continue this volatile cycle of ups and downs?