After suffering a serious knee injury in 2005, Rainer Schuettler has been battling to stay healthy rather than go for the titles. Ranked as high as No 5 in the world three years ago, the German's ranking began to slip since then.

On the mend now after the surgery, the 31-year-old could not have chosen a better stage to announce his return to big-time tennis than the $416,000 Kingfisher Open ATP Tour event here on Friday.

Ranked 143 on the ATP list and coming into the quarterfinal clash against former world No 1 Lleyton Hewitt with just four wins on the Tour this season, Schuettler was not even expected to test his second-seeded opponent.

But what happened after that was certainly not in the script. The German not only made a mockery of the seeding, but handed the Aussie — himself making a comeback — a straight sets defeat on a surprisingly dry day at the CCI courts.

The German's 6-3, 7-5 victory earned him a semifinal meeting against Olivier Rochus. The Belgian had advanced after Nicolas Kiefer retired due to gastroenteritis when down 1-4 in the opening set.

The other semifinal will be an all-French affair. Top-seeded Richard Gasquet went through to the last four stage with a 6-2, 6-4 win over Austria's Stefan Koubek. Fabrice Santoro outplayed fourth-seeded Jarkko Nieminen of Finland 6-3, 6-4 in the other quarterfinals.

A finalist in Chennai seven years ago, Schuettler relies on his service returns to have his opponents in trouble. That was on view for the better part of the one-hour 36-minute encounter against Hewitt, who has a solid serve.

But on the day, that didn't work for the second-seeded Australian. He struggled right through with his serves, getting only 32 percent of his first serves in. That suited the German fine. He had no problems in making sizzling returns on Hewitt's weak second serves. That was the key between a victory and defeat on the day.

"It's hard to dictate play against him," said a disappointed Hewitt. "He played some great tennis and some average tennis. But he played as if he didn't care and went for his shots and it worked for him," the Aussie added.

It sure did after a slow start. Schuettler was broken in the very first game of the match. But he broke back in the fourth and then began playing like a man possessed. Besides his awesome returns, Schuettler made some unbelievable winners on both flanks to have Hewitt in all kinds of trouble.

Surprisingly, many in the stands too shifted allegiance – they were right behind the better player. Schuettler broke Hewitt in the sixth game before wrapping up the first set. For a brief while in the second set, errors crept into his game. With a couple of calls too going against him, Schuettler momentarily lost his focus and was down 2-5 and down 15-40 on his serve.

The German saved both set points and broke the struggling Hewitt in the ninth and 11th games. Hewitt made a last-ditch effort, going up 30-15 on Schuettler's serve. The German came up with a brilliant forehand down-the-line passing shot on the run to make it 30-30. The stunned Aussie had that 'hey, how did you pull that off' look on his face. Schuettler then came up with a huge serve and a backhand winner later to make his first semis of the year.

Results (all quarterfinals): Singles: Fabrice Santoro (Fra) bt Jarkko Nieminen (Fin) 6-3, 6-4; Richard Gasquet (Fra) bt Stefan Koubek (Aut) 6-2, 6-4; Olivier Rochus (Bel) bt Nicolas Kiefer (Ger) 4-1 (retd.); Rainer Schuettler (Ger) bt Lleyton Hewitt (Aus) 6-3, 7-5.  Doubles: Patrick Briaud (US)/ Wesley Moodie (RSA) 6-4, 7-6 (7-3); Robert Lindstedt (Swe)/ J Nieminen bt James Auckland/ Ross Hutchins (GBR) 7-5, 6-7 (7-9), (retd.); Lars Burgsmuller (Ger)/ Olivier Rochus (Bel) bt Yves Allegro (Sui)/ Kristof Vliegen (Bel) 7-5, 7-6 (7-5).