American Taylor Fritz moved into the Wimbledon quarterfinals for the third time in four years on Sunday, advancing when his injured opponent, Jordan Thompson, retired while trailing 6-1, 3-0 after 41 minutes.
With Fritz advancing, it's the fifth consecutive major in which at least one American man has made the quarterfinals -- the longest streak for the U.S. men since a run of six straight from the 2002 US Open to 2004 Australian Open.
The unseeded Thompson's movement and power clearly were compromised. The Australian entered the match with back and leg issues and left the court for a medical timeout in the second set, then stopped after trying to play for three more points.
"Just got significantly worse today," said Thompson, who was competing in singles and doubles at Wimbledon. "Just played a lot of tennis on a body that shouldn't have been, and it just took its toll."
Thompson has had a couple of retirements at majors before, most recently the 2023 US Open against Botic Van De Zandschulp because of a leg injury. He was also forced to exit his 2021 Australian Open match against Casper Ruud with a shoulder injury.
For the No. 5-seeded Fritz, it was a shorter workday after playing a pair of five-setters and one four-setter earlier in the tournament.
"It's obviously not the way that I want to go through," Fritz said. "It's just sad. ... Respect to him for coming out. His body's not right."
Fritz and Ben Shelton, who advanced to the round of 16 with his straight-sets win Saturday, are the only Americans remaining in the men's singles draw. Looking ahead, only two American men in the past 15 years have reached the Wimbledon semifinals: Sam Querrey in 2017 and John Isner in 2018.
Fritz next faces Russian 17th seed Karen Khachanov, who reached his second Wimbledon quarterfinal by beating Kamil Majchrzak 6-4, 6-2, 6-3 earlier Sunday.
"To be honest, today was a really great performance -- at least from my side," said Khachanov, who finished with more than twice as many winners as unforced errors (44-21).
The 109th-ranked Majchrzak was playing in a fourth-round match at a major for the first time. He was on a six-match Grand Slam losing streak before Wimbledon.
Khachanov has been a Grand Slam semifinalist twice, at the US Open in 2022 and the Australian Open in 2023. Fritz made it that far for the first time when he got to the final at Flushing Meadows in September before losing to No. 1 Jannik Sinner.
Fritz is 12-1 on grass this season, having won titles at Stuttgart and Eastbourne. His 12 tour-level grass match wins are the most by any American man in a season since Pete Sampras won 12 in 1999 at Queen's Club and Wimbledon.
In other fourth-round men's action, the last British singles player, 2022 semifinalist Cam Norrie, advanced with a 6-3, 7-6 (4), 6-7 (7), 6-7 (5), 6-3 win over qualifier Nicolas Jarry of Chile, a match that lasted 4 hours and 27 minutes.
The 61st-ranked Norrie, who played college tennis at TCU in Fort Worth, Texas, will go up against two-time defending champion Carlos Alcaraz or No. 14 Andrey Rublev for a spot in the semifinals.
Norrie, who joined Tim Henman (1996) and Greg Rusedski (1997) as unseeded British men to make the Wimbledon quarterfinals in the Open era, withstood 46 aces from Jarry, the most by any player in a match at this year's tournament.
"At the beginning of this year I was I was struggling a little bit with confidence, I had some doubts, and I just wanted to enjoy my tennis a little bit more and I'm doing that," Norrie said. "It was a bonus to win but I'm more happy that I was enjoying it."
ESPN Research and The Associated Press contributed to this report.