Groth dumps out Mahut

Unseeded Australian Samuel Groth upset defending champion Nicolas Mahut at the Hall of Fame Tennis Championships on Thursday to advance to his maiden ATP World Tour semi-final.

The 26-year-old's 6-3 6-4 victory over fourth-seeded Frenchman Mahut in Newport, Rhode Island, secured him a semi-final clash with second seed Ivo Karlovic.

It also ensured he will rise into the world's top 100 next week, and guaranteed him direct entry to this year's US Open.

"I've got myself in great shape," said Groth, who won 82 per cent of his first serves and capitalised on the only two break points of the quarter-final encounter. "I'm not losing my mind out on court.

"I'm doing a lot of things better," he added on after the 77-minute contest.

"I've tightened up my groundstrokes. I'm volleying better than I ever have. I'm making it tough for guys to break me. I'm becoming more prepared to be a top player."

Mahut acknowledged: "(Groth) played well today. I have to congratulate him. He was too good and too consistent for me."

Karlovic did not have it all his own way against Dudi Sela, but advanced in the end with a 7-6 (7/3) 7-5 win over the Israeli in 93 minutes.

Looking ahead to the last-four tie, the Croatian said: "It will be a difficult match. [Groth] will hit a lot of aces, we'll have a couple of tie-breaks. It can go either way and hopefully it will be a nice one."