Isner survives Atlanta scare
Top seed John Isner had to save two match points before finally seeing off the challenge of fellow American Robby Ginepri at the Atlanta Open.
The defending champion had been on the brink of bowing out at the second round stage as he trailed 15-40 and 5-4 in the deciding set.
However Isner found two big serves when it mattered the most and he was able to hold on to level the set.
Isner then broke Ginepri for the first time in the match before safely sealing a 4-6 7-6 (7-5) 7-5
"I was a nervous wreck out there but fortunately for me I was able to hit two big serves and bring that game back to deuce and it really turned the match around," Isner said.
"He returns very well, that's what he does best, and he was giving me fits on my serve tonight.
"I actually served a lot better as the match progressed, and I had to because he was returning well, and that last game, I can't serve any better than that."
Lucky loser Thiemo De Bakker recorded a massive upset by ousting second seed Kevin Anderson in straight sets.
The 25-year-old from Holland raced to a 6-4 7-5 victory, leaving world No 17, who lost to Isner in last year's final, wondering what happened.
"I didn't feel like my normal serve out there," Anderson said.
"I felt a step behind the whole match. I thought he played well, hit the ball quite big. I was disappointed with how I played."
Seventh seed Yen-Hsun Lu also bowed out after losing 6-4 6-3 to Benjamin Becker, who set up a quarter-final showdown with De Bakker.
Marinko Matosevic, the eighth seed, avoided joining the exodus of ranked players as he beat American Tim Cmyczek 6-4 7-5.