INDIAN WELLS, Calif. -- Taylor Fritz defeated Spanish qualifier Jaume Munar 6-4, 2-6, 7-6 (2) on Tuesday in the third round of the BNP Paribas Open, making him one of five American men still alive in the desert tournament.
Fritz reached the semifinals at Indian Wells last year, his career-best result in an ATP Masters 1000 event. The son of former WTA Tour pro Kathy May has been on an upward trajectory since, reaching the fourth round of the Australian Open in January -- his best showing yet in a Grand Slam event.
John Isner beat 14th-seeded Diego Schwartzman 7-5, 6-3 to reach the fourth round. The 6-foot-11 American capitalized on his 16-inch height advantage, blasting 13 aces and frustrating Schwartzman with clever drop shots. Isner didn't even need any tiebreakers; 18 of his 30 sets played this year have ended in tiebreakers.
Two other Americans, Tommy Paul and wild-card Steve Johnson, got beat. Paul lost to 29th-seeded Alex De Minaur 7-6 (2), 6-4. Johnson dropped a 7-6 (7), 6-3 decision to 11th-seeded Hubert Hurkacz.
"Tommy is really close to cracking into being seeded at slams," Fritz said. "Reilly [Opelka] is consistently beating very, very good players. It's not weird to see these guys beating really good players, having solid results."
American Frances Tiafoe lost to No. 7 seed Andrey Rublev 6-3, 6-4.
On Wednesday, two more Americans have big fourth-round matches. No. 17 seed Opelka plays 21-time major champion Rafael Nadal, while Jenson Brooksby takes on defending champion and 12th-seeded Cameron Norrie.
"For the first time in a while you can actually say American tennis on the men's side is very promising,'' Isner said. "We have a lot of players in the top 100. I do think getting two players in the top 10 sometime in the near future is very conceivable."
In women's fourth-round action, Madison Keys beat British qualifier Harriett Dart 6-1, 6-4. Keys is the last American woman still in the tournament.
"I really just kind of buckled down,'' Keys said. "If I got a second serve, I was going to be more aggressive. When I got the opportunity, I was going to go for it.''
No. 3 seed Iga Swiatek outlasted three-time major champion and former No. 1 player Angelique Kerber 4-6, 6-2, 6-3.
"I felt like she wanted to use her experience and kind of trick me,'' Swiatek said. "I like that because it's like a new experience for me. I'm pretty proud of myself that I could win against such a smart player.''
Defending champion Paula Badosa defeated Leylah Fernandez 6-4, 6-4 to reach the quarterfinals.
Simona Halep, the 2015 champion, beat Sorana Cirstea 6-1, 6-4. The Romanians played for the first time in 12 years and have split their four meetings.
"I feel like I played perfect in the first set,'' Halep said. "The second set was a little bit tougher because I started to miss. She started to play a little bit better. But I think it's a strong victory for me.''
Petra Martic of Croatia beat No. 28 Liudmila Samsonova 7-6 (6), 6-4. No. 6 Maria Sakkari advanced when qualifier Daria Saville retired trailing 4-1 because of a left thigh injury.