Serena Williams faces a dangerous opponent in her third-round match: fellow American Danielle Collins, who reached the quarterfinals in the tournament last September before losing to Sofia Kenin. Williams narrowly beat Collins in their only previous meeting at a tournament in Australia early this year. Collins, ranked 50th, beat a qualifier in her first two matches this week. Williams is again seeking a record-tying 24th Grand Slam singles titles. American Madison Keys, a semifinalist at Roland Garros in 2018, seeks a spot in the fourth round when she faces former No. 1 Victoria Azarenka. Four American men will be in action, including No. 31-seeded John Isner and No. 32 Reilly Opelka. Isner will face No. 5 Stefanos Tsitsipas. Four American men made it to the third round at Roland Garros for the first time since a half-dozen advanced that far in 1996.