NEW YORK (AP) The very first Grand Slam loss of John Isner's career - back when he was ranked 184th, only a few months removed from leading Georgia to an NCAA tennis title, and still officially listed at 6-foot-9 - came against none other than Roger Federer.
It was at the 2007 U.S. Open, and Isner actually managed to win the first set before being beaten in four.
They'll meet again at Flushing Meadows on Monday night in Arthur Ashe Stadium, this time in the fourth round, and plenty has changed for Isner.
For one thing, he is now the top American man, seeded 13th in this tournament. He's best known for winning the longest match in tennis history over Nicolas Mahut - 11 hours, 5 minutes over three days, finishing 70-68 in the fifth set at Wimbledon in 2010 - and generally has shown a propensity for participating in ''It won't seem to end'' encounters.
He's also now officially 6-10, according to the ATP.
But the most significant difference heading into Monday is that Isner gives himself a chance against Federer. That wasn't the case eight years ago, long before Isner actually did defeat Federer in a Davis Cup match.
''I honestly probably didn't believe I could beat him. ... I was happy to be on that court. I was fresh out of college and no one knew anything about me. He certainly didn't. I won one set, which was incredible. Didn't win much after that,'' Isner said. ''Can't draw on that at all, really. I'm a different player. I'm a much better player.''
His serve is as good as ever, and he hasn't been broken in a U.S. Open match since 2013.
''Obviously, John can hold easy, that we know. That I can hold my serve a lot and stay very focused, that I know as well,'' Federer said. ''That's part of trying to beat him, as well, is just to stay with him. He also wants to break, and he gets frustrated - like any other big server, as well, if they can't get a break, because they also don't want to play `breaker after `breaker.''
Against someone like Isner, it will be intriguing to see whether Federer decides to try out his new tactic on opponents' second serves, charging forward to take a return that essentially is a half-volley. Federer and his team have given the move the nickname ''SABR,'' which stands for ''serve attack by Roger.''
Here's what else to watch at the U.S. Open on Monday:
YOUNG VS. WAWRINKA
There will be another American vs. Swiss rematch in Arthur Ashe Stadium: 68th-ranked Donald Young vs. fifth-seeded Stan Wawrinka, a two-time major champion. The only other time Young reached the fourth round at a Grand Slam tournament was when he did it at the 2011 U.S. Open, and he beat Wawrinka in the second round along the way. Before this year's U.S. Open, Young had never come back from two sets down to win a match - he did it twice during Week 1. Marked for stardom as a teen, Young is now perhaps fulfilling his promise. ''I've kind of been beat up. I've beat up myself. I've kind of been down. I've had good times, bad times. Just some resilience and fighting,'' said the 26-year-old, who is based in Atlanta. ''Hopefully it's not over and there's more to come.''
The winner of Federer vs. Isner will play No. 6 Tomas Berdych of the Czech Republic or No. 12 Richard Gasquet of France in the quarterfinals. The winner of Wawrinka vs. Young faces 2012 U.S. Open champion Andy Murray or No. 15 Kevin Anderson of South Africa. In fourth round of the women's tournament, this Monday's schedule: No. 2 Simona Halep of Romania vs. No. 24 Sabine Lisicki of Germany, two-time Wimbledon champion Petra Kvitova vs. Johanna Konta of Britain, 2011 U.S. Open champion Sam Stosur vs. No. 26 Flavia Pennetta of Italy, and two-time major champion Victoria Azarenka vs. Varvara Lepchenko of the U.S.
Follow Howard Fendrich on Twitter at http://twitter.com/HowardFendrich