JOHNS CREEK, GA. (AP) - No. 2 seed John Isner 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.
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.
Isner had not played since he lost in the second round at Wimbledon the day after his record win over Nicolas Mahut of France.
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.
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.
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. The tour's leader in aces pushed his 2010 total to 705 with 33 against Muller.
Isner 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.
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.
Dent will face the winner of Mardy Fish's match against Robby Ginepri.