JOHNS CREEK -- It wasn't quite the marathon he had to go through at Wimbledon earlier this summer, but John Isner had to put in a full day's work in his first singles match at the Atlanta Tennis Championships.
The former Georgia Bulldog was on the ropes after dropping the first set to Gilles Muller, but battled back to outlast the qualifier in two straight tiebreakers and take a 4-6, 7-6 (6), 7-6 (7) second-round win Wednesday at the Atlanta Athletic Club.
Muller was nearly the day's second major upset after American Taylor Dent spotted Argentina's Horacio Zeballos the first set before roaring back for a 4-6, 6-2, 6-0 win over the No. 4 seed.
For Isner, who gained world acclaim with his first-round win over Nicholas Mahut of France in the longest match in tennis history at Wimbledon last month, it was another long day at the office -- two hours and 33 minutes, the longest match of the tournament so far.
"Well, it was two hours and something (Wednesday)," the 6-foot-9 North Carolina native joked. "But like I said ... (Tuesday), usually I compete pretty well. That's what keeps me in these (marathon) matches. That's when you see them a lot (even) when I'm not playing my best. The way I compete kind of keeps me in it."
Both players competed well Wednesday, trading serves throughout, with Isner successful on 65 percent of his first serves, winning 72 percent of his service points and adding 33 aces, compared to 70 percent first serves, 78 percent service points and 29 aces for Muller.
In fact, there was only one break of serve throughout the entire match.
And Isner was put under serious pressure in the first set when he sent a ball into the net to give Muller that break to go up 5-4, and the lefty from Luxembourg took advantage by holding serve to take the first set 6-4.
Muller had several key opportunities to gain another break early in the second set, which had the near-capacity crowd at the 5,500-seat stadium court -- including many wearing Georgia Bulldog red, plus several celebrities like local women's world-ranked player Melanie Oudin, Isner's former coach at UGA Dan McGill and Carolina Panthers receiver Steve Smith -- mostly quiet and on edge.
"The crowd was great (Wednesday) night," Isner said. "I heard a lot of barks out there. ... I was able to use them to kind of pull me through because this match was pretty ugly, to be honest.
"I'm down break points a couple times in the second set. And with the way he's serving, those are essentially kind of like baby match points. ... The crowd would kind of pump me up ... and cheer me on. I just didn't want to let them down."
And Isner dug deep and held off Muller on six break points in the second set before forcing the tie-breaker.
"I had a lot of chances to win the match," Muller said. "Every break point I had in the second set, or every match point, (Isner) was serving. And every time, he served a first serve. To be honest, I think there's nothing I could do about it ... He was just serving good, and that's it."
In the tie-breaker, the two players battled each other for 13 points before Isner finally got a mini-break on Muller to win 8-6 and send the match to a third set.
If that set didn't evoke memories of Isner's Wimbledon marathon, the third set did.
Once again, the two players traded service holds to go past regulation, though this time, there was a tie-breaker for Isner.
And once again, he had to come from behind, this time battling back from Muller's early mini-break that gave him a 4-1 lead and eventually getting that mini-break back when Muller -- playing for the fifth straight day after coming through the qualifying bracket -- double-faulted up 5-3.
Isner finally came up with the big points, two straight aces -- including one on match point -- with Muller leading 7-6 to take an 8-7 lead.
And when Muller's sent a cross-court backhand wide, Isner had won, improving to 16-5 all-time in final-set tie-breakers.
The long match pushed the other feature match of the evening between sixth-seeded Mardy Fish and Marietta native Robby Ginepri late into the night beyond press time.
It also came on the heels of the biggest upset of the tournament thus far with Dent taking out Zeballos after dropping the first set.
Dent responded by breezing through the final two sets to move on to play either Fish or Ginepri in the quarterfinals.
"I'm always amazed at how it's a combination of factors (in a momentum switch)," said Dent, who moved into Friday's quarterfinals -- his first quarterfinal appearance in an ATP event since 2005 in Tokyo -- to take on Fish/Ginepri. "His level (of play) dropped just half a notch, maybe a notch, and my level rose half a notch to a notch. That was the difference.
"It's funny. Scores can be so misleading. It doesn't take much to run away with a tennis match."