Top seed Rainer Schuettler stormed into the semi-finals of the Japan Open with an efficient 6-3, 6-3 win over Australian Scott Draper on Friday.

However, Wimbledon finalist Mark Philippoussis was forced to retire from the $860,000 Tokyo tournament with a sore neck while trailing Frenchman Cyril Saulnier 5-2 in the first set.

The Australian, who won in Shanghai at the weekend, sustained a stiff neck after sleeping awkwardly on Thursday night.

Schuettler, closing in on a spot at the season-ending Masters Cup, was razor-sharp from the baseline and solid at the net. He took just 68 minutes to win in sweltering conditions.

The Australian Open runner-up saved a break point at 3-3 in the second set with a brilliant reflex volley that took the wind out of Draper.

The German wrapped up victory soon after the turnaround, forcing his opponent into a wild return on his first match point.

"He beat (sixth-seeded German Nicolas) Kiefer, so I knew I had to be aggressive and put pressure on him from the start," said Schuettler, chasing his first ATP title of 2003.

"I was trying to go for my shots and dominate the rallies and it worked. I played two pretty good sets."

Schuettler will face the unseeded Saulnier on Saturday after an injury time-out failed to relieve the discomfort for Philippoussis.

NECK PAIN

"It was my neck. I woke up, went to the bathroom and ended up sleeping on my stomach," said fifth seed Philippoussis, whose career has been plagued by injuries.

"I woke up the wrong way...and the more I served, the worse it got. It just got stiffer and the pain got worse. It will probably be around for two days at most."

Third seed Paradorn Srichaphan was two points away from defeat against close friend Lee Hyung-taik but the 24-year-old Thai battled back to squeeze out a 4-6, 7-6, 6-3 win over the seventh-seeded South Korean.

Lee, who memorably won his first ATP title in Sydney a week before being destroyed 6-1, 6-0, 6-0 by Andre Agassi at the Australian Open in January, suddenly fell apart at 5-5 in the second-set tiebreak.

Paradorn, who has won two tournaments this year, quickly gained the decisive break in the first game of the final set and closed out the match after two hours and 15 minutes with an unplayable return off a weak second serve from Lee.

Among the women, fast-rising Maria Sharapova moved a step closer to her first WTA Tour title with a hard-earned 7-5, 7-6 win over Claudine Schaul of Luxembourg, the 16-year-old Russian storming through the second-set tiebreak 7-1.

The Florida-based Sharapova will face Zheng Jie in the semi-finals after the Chinese player beat compatriot Yan Zi 7-6, 6-3.