Naomi Osaka advanced to the US Open fourth round for the third time this year with a 6-3, 3-6, 7-5 win over Elise Mertens. The former champion, who won titles in 2018 and 2020, now faces Australian Open winner Elena Rybakina on Monday. Rybakina will become world No. 1 if she reaches the semifinals, adding pressure the Kazakh player must manage.

Osaka, playing with freedom after a consistent season (28-10 record), pushed Rybakina to three sets in Toronto weeks ago. Both possess big serves and aggressive groundstrokes, though Rybakina holds a power edge. Osaka thrives on New York crowds and night sessions, saying she plays best when focused on fun and point-by-point tennis. "I know she's one of the best players in the world, so I have no choice but to come with a high level," Osaka said.

The match pits Osaka's experience and crowd support against Rybakina's ranking stakes and firepower.