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.

UAE Team Emirates-XRG's Wellens takes Tour of Britain lead
Zverev reaches US Open fourth round with win over Tabilo
Rybakina sets up Osaka showdown at US Open
Man City make it three wins in a row, Palace earn first points
Alpine's Gasly seizes first career F1 pole ahead of Russell at Monza
