JOHNS CREEK, Ga.(AP) -- John Isner did what he does best - pull out a long tennis match.
Isner, the No. 2 seed, fought through another final-set tiebreaker with a 4-6, 7-6 (6), 7-6 (7) victory over Gilles Muller of Luxembourg in the second round of the Atlanta Tennis Championships on Wednesday night.
``I was able to play well when I needed to early in the second set, and the crowd would pump me up when I'd get down 15-40,'' he said. ``I just didn't want to let them down. I didn't want to lose my first match here.''
Isner, who became a household tennis name after winning a three-day, 183-game match at Wimbledon last month, improved to 16-5 in career final-set tiebreakers.
He had not played since losing in the second round at Wimbledon the day after his record win over Nicolas Mahut of France.
``With Gio as my opponent, he's probably one of the last guys I want to play,'' Isner said. ``First match back (against) a big-serving left-hander, he's not going to give you much rhythm. So that was a little bit working against me, but I just told myself to compete.''
Michael Russell will face Isner in the quarterfinals on Friday night.
Down a point in the third-set tiebreaker, Isner did not react to a fan who shouted ``70-68, baby!'' - the score of the 6-foot-9 former Georgia standout's fifth set at the All-England Club.
Isner responded with his racket, though, winning the next two points when Muller hit errant returns and taking the match when Muller's backhand volley fell wide right.
``This win was huge,'' said Isner, who earned his first career ATP tour title earlier this year in Auckland. ``Maybe one of the biggest of the year because I want to get some matches under my belt before going on to (Washington) D.C. and the two masters series events and the U.S. Open.''
Taylor Dent beat No. 4 seed Horacio Zeballos 4-6, 6-2, 6-0 in an earlier match to advance to his first ATP tour quarterfinal since Tokyo in October 2005. The victory was his seventh in 20 matches this year.
Dent will face No. 6 seed Mardy Fish, a 6-1, 7-5 winner over Robby Ginepri.
Zeballos, voted the tour's top newcomer in '09, lost despite inconsistent service from Dent, whose 22 double-faults over the last two days pushed his total this year to 122.
``Unfortunately, double-faults have always been a staple of my game,'' Dent said. ``I enjoy giving away a few free points, but any time you try to improve or thinker with things - I'm trying to improve my accuracy a lot with my serve, both first and second - you're going to have a dip-down period.''
Isner, now a tour-best 23-12 in tiebreakers this year, improved to 25-15 overall in 2010. He is ranked No. 19 on the ATP tour and the second-leading American behind Andy Roddick, Atlanta's top seed.
The tour's leader in aces, Isner pushed his 2010 total to 705 with 33. He won the second-set tiebreaker by taking the final three points, the last coming on Muller's long volley. But Isner struggled all night against the serve of Muller, who had 29 aces on the hardcourt surface.
``He was obviously hitting his spots very well,'' Isner said. ``Being tall like he is and a left-hander, everyone hates trying to return that serve - the one out wide, the slider - but it wasn't that I was giving it to him. He was just hitting his spots.''
Russell's 1-6, 6-2, 7-5 victory over Rainer Schuettler was his first over the German in three career matches, their first since September 2001 in Hong Kong.
Fish, who won on grass two weeks ago in Newport, R.I., to earn his fifth career tournament victory, saved all six break points. He improved to 25-11.