NEW YORK -- After tearfully addressing the capacity crowd at Grandstand, and needing multiple moments to compose himself, John Isner gave one more hug to Michael Mmoh, the man who ended his career, and took a deep breath.
He then grabbed his bag, waved to the crowd -- who remained on their feet, showering him with applause -- and slowly walked off the court, as if he wasn't quite ready for it all to be over.
But Isner's storied singles career had come to an end, after nearly four hours and a 3-6, 4-6, 7-6 (3), 6-4, 7-6 (7) loss to Mmoh in the second round of the US Open on Thursday.
The 38-year-old Isner tweeted last week he would be retiring following the tournament. "After 17+ years on the ATP Tour, it's time to say goodbye to professional tennis," he wrote. "This transition won't be easy but I'm looking forward to every second of it with my amazing family."
After 17+ years on the @atptour, it's time to say goodbye to professional tennis. This transition won't be easy but I'm looking forward to every second of it with my amazing family.— John Isner (@JohnIsner) August 23, 2023
The @usopen will be my final event. Time to lace 'em up one last time. ❤️ ♥️ 💜 pic.twitter.com/GyRTXGNK8G
Thursday's defeat marked the end of a notable chapter for not just Isner, but for American men's tennis.
After a successful collegiate career at Georgia, in which he won the NCAA doubles title in 2005 and the team title in 2007, Isner turned pro in 2007 and quickly made a name for himself. Peaking at No. 8 in 2018, he recorded 16 singles titles and a Wimbledon semifinal appearance. Known for his incredible serve, Isner has the most aces in tour history (14,470) and also notched the ATP's fastest official serve at 157.2 miles per hour.
He's also known for his victory in the longest professional tennis match in the sport's history. Isner defeated Nicolas Mahut during the first round at Wimbledon in 2010 in a match that needed five sets, 183 games and more than 11 hours on court spread out over three days. The feat is commemorated by a plaque that remains outside the court at the All England Club.
But despite his trophies and spots in the record books, Isner's most valuable contribution might be the role he played for American men's tennis during an unusually challenging stretch following the retirement of Andy Roddick. While he was unable to win a major like Roddick did in 2003, for years Isner was the top-ranked American man and its most reliable star.
"I mean, when I was a junior, then for a long time when I first started playing, started my pro career, he was the guy," said 25-year-old Taylor Fritz, who is currently the top-ranked American man at No. 9. "He's been on top of American tennis for a really long time. He was always super nice, [and] welcoming to all of the new younger guys like myself and Reilly [Opelka] and Tommy [Paul]. He was always really welcoming to us as someone we looked up to."
While other American men would have a strong season or period, Isner was consistently at the top of the game. From 2010 to 2019, he finished the year within the top 20. For eight of those seasons, he was the top-ranked countryman. While the now-20-year streak without a major title remains a talking point among American men, Isner provided a motivating spark for those following behind him.
"[I] grew up watching John obviously," Frances Tiafoe, 25, said Monday. "Watching him play the Legg Mason back in the day, as it used to be called in D.C., how solid he was. He was a hell of a player for so many years, top 20 a lot of his career, winning 250s for fun. He was a great leader for American tennis."
Fritz and Tiafoe are now both in the top 10 -- a first for American men in over a decade -- and there are eight Americans in the ATP's top 50. Tiafoe and Paul have both reached major semifinals -- matching Isner's best result at a Slam -- in the past year. Martin Blackman, the USTA's general manager of player development, believes it was Isner who in part helped set the tone for the younger generation.
"After Andy, we were so fortunate to have John have these breakthrough moments and constantly reaching the top 10," Blackman said. "He's been a great example of professionalism and keeping the bar high for these [young] guys."
While being the face of men's tennis in a country with several legendary names in its past couldn't have been easy, Isner said he didn't feel the weight that some might expect.
"I never felt like it was a burden to be the No. 1 American," Isner said Friday. "Maybe because I wasn't, like, in juniors and through college real spoken about. I think in a sense I sort of came on tour with not much pressure on myself. Of course, there weren't many expectations for me. That helped me out a lot.
"Of course, I did take pride in being the best I could be. I always did want to be the No. 1 American. I'd be lying if I told you I didn't. [But] I never felt like there was this huge, enormous burden on me to try to get there."
Isner has spoken this week about his optimism for the future of American men's tennis, and it was on display in the loss to the 25-year-old Mmoh, a compatriot who is having the best season of his career and reached his first US Open third round with the victory. Mmoh called it "the biggest win of my career" after the match, as Isner sat in his chair several feet away sobbing into a towel.
However, Isner's time as a professional tennis player isn't quite done just yet. He is playing doubles later Thursday, potentially for the last time, with friend and fellow American Jack Sock, who is also retiring after the US Open. The duo has won three Masters 1000-level titles together and could just find some last-minute magic in New York. But no matter how they fare, Isner has no doubts about this being his final tournament.
"I'm certain," he said. "My [retirement announcement] tweet has like 5 million views or something like that. I'm done."