Isner, who is gunning for his 10th ATP title, will face fifth seed Marcos Baghdatis who beat Gilles Muller 6-7(4) 6-3 7-6(4).

Top seed Isner stayed on track for his third consecutive Atlanta title when he outlasted fellow American Denis Kudla in blazing heat on the outdoor hardcourt.

Isner, top-seeded at the event, has been in the finals of the Atlanta Open 4 of the last 5 years.

Muller made the Atlanta final in 2012 when he was beaten by Andy Roddick.

“He is solid, very quick”, Isner said about Kudla. “I’ve generally played better as the tournament goes on and I hope that’s the case”. It’s hard to say if Isner’s bye in the first round will be to his advantage or not: he hasn’t played as much as Kudla, so he should be more physically fit for the semis, but Kudla fought to this point through three matches, showing he has determination. The 2.08m-tall former University of Georgia player’s serve peaked at 222kph. He has had a history of injuries and was ranked as high as No. 8 in the world approximately nine years ago. His quarterfinal match against second-seeded Vasek Pospisil took two sets, where he won the first set 6-4 and took the second-set tie-breaker with 7-5.

The American beat Czech tennis player Radek Stepanek 7-6 (3), 7-6 (7), reports ABC News. I felt like I did that out there, for the most part. “There were a lot of short points, which generally works in my favor”.

Gasparyan served for the match when up 5-4 in the second set but was broken back at love.

Nadal is playing in Hamburg for the first time since 2008, when he won the trophy with victory over Roger Federer, as the left-hander looks to breathe life back into his flagging season. “I got stronger and stronger as that match went on”.

Seppi, who knocked Federer out of the Australian Open this year, enjoyed a walkover into yesterday’s semi-finals when compatriot Simone Bolelli withdrew due to gastroenteritis.

Baghdatis nevertheless has to be pleased with his run in Atlanta.

“I thought I served well in the big moments and played well in the key points to give myself an opportunity to be on offense”.