Two-time champion Naomi Osaka overcame a flurry of mistakes to fight past Czech Katerina Siniakova 6-2 5-7 6-1, finding her mettle to reach the third round of the US Open on Thursday.
The 13th seed has spent years taming her own tendency toward self-recrimination, and showed the best evidence of her new career outlook as she reclaimed her composure with a bathroom break before the third set at Arthur Ashe Stadium.
"The match was definitely really tough. I don't know, I just felt like I had to fight," said Osaka, who will next play Belgian Elise Mertens, who registered a 6-2 7-6 (5) win over Uzbekistan's Maria Timofeeva.
Elsewhere, Iga Swiatek displayed complete control as the 2022 champion dispatched Argentinian Nadia Podoroska 6-3 6-2 to advance to the third round.
The Polish eighth seed sealed the victory in one hour and 10 minutes.
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