SYDNEY: Big guns John Isner and Gilles Simon tumbled out of the Sydney International yesterday as Jarkko Nieminen stayed on course to defend his title.

Towering number one seed Isner crashed out 6-4, 6-4 to fellow American Ryan Harrison in the second round and raised doubts about whether he will play in next week’s Australian Open with a bruised right knee.

French second seed Simon bowed out of the tournament without hitting a ball, succumbing to a recurring neck injury and giving an opportunity to lucky loser Ivo Klec to face Nieminen.

Finland’s Nieminen polished off the Slovakian world ranked 416th player 6-3, 6-1 in just 46 minutes to set up a quarter-final showdown today with in-form Australian Bernard Tomic.

Big-serving Isner, who withdrew from last week’s mixed teams Hopman Cup in Perth with the injured knee, said he had a decision to make about playing in the year-opening Grand Slam in Melbourne.

“It’s better. Definitely better than I thought, but it’s not 100 %,” Isner said. “I don’t know. I’ve got a decision to make shortly.

“It needs rest. That’s what I’ve done. That’s the only thing I’ve done ever since I felt it last week.

“I will need to take time off somewhere. That’s a given. It’s not just going to heal. I can’t play all the way through and have it heal.”

Simon also has injury concerns ahead of the Australian Open but is more confident than Isner of playing in Melbourne.

“I made a bad move yesterday playing in the doubles during the tie-break and it’s not the first time it’s happened to me,” said Simon, who won this event two years ago.

“I have time if I don’t have any complications. It’s really difficult for three or four days so it should be right although it’s not the best preparation for the Open.”

Nieminen will face a tough test against Tomic, who knocked out German fifth seed Florian Mayer, 7-6 (7-4), 6-2.

“Tomic has started the year really well. I think he hasn’t lost a match,” Nieminen said.

“It wasn’t a tour event, but he beat (Novak) Djokovic and other good players at the Hopman Cup and he played well yesterday. I think he has improved a lot physically.”

Tomic gained revenge over German nemesis Mayer, who crushed him in straight sets in Australia’s Davis Cup World Group playoff loss in Hamburg last September.

Frenchman Julien Benneteau, who lost to Nieminen in last year’s final, strolled into the quarters against Harrison after his sixth seeded opponent Radek Stepanek quit with a strained upper back after playing just four points.

In the women’s event, Poland’s Agnieszka Radwanska clinched a seventh straight victory to reach the semi-finals yesterday, as she builds towards next week’s Australian Open.

The world number four and tournament top seed overcame Italian world No. 16 Roberta Vinci, 6-4, 7-5 in just over an hour and a half to move into the last four.

Radwanska, coming off victory in Auckland last week where she beat Yanina Wickmayer in the final, will now face 2011 winner Li Na of China. Li Na took two hours and 19 minutes to down teenage American qualifier Madison Keys, 4-6, 7-6 (7-2), 6-2 in a night match.

In the bottom half of the women’s draw, Slovakian world number 15 Dominika Cibulkova upset French Open finalist and tournament third seed Sara Errani of Italy, 6-2, 6-1.

Cibulkova, who eliminated 2011 Wimbledon champion Petra Kvitova in the opening round, will face either German second seed Angelique Kerber or former US and French Open champion Svetlana Kuznetsova in the semis. — AFP

• Please wait.

• Make betting legal, says top Indian body
• NBA: Pacers edge Heat to even series
• Arat: Istanbul bid to host the 2020 Olympic is about building bridges
• Golf: Two share lead at inaugural rain-hit Pure Silk LPGA
• Golf: Kuchar leads weather-hit Colonial
• Kuchar one ahead at weather-hit Colonial
• Woods heads potent field for next week's Memorial
• Squash: Matthew offers a message with a warning
• Golf: Molinari leads but Ryder Cup colleagues crash out
• Tennis: Djokovic blocks Nadal path to Paris super eight