Aussies Matt Ebden and Marinko Matosevic have missed out on the quarter-finals of the Swiss Indoors.
Ebden suffered a 6-3, 6-1 defeat to Russian Mikhail Youzhny, who convincingly eliminated Bernard Tomic in the first round of the tournament in Basel.
Matosevic lost a big-serving showdown with towering South African Kevin Anderson 6-3, 6-7 (5-7), 6-3.
Juan Martin del Potro secured his place in the ATP World Tour Finals with a 7-5, 6-1 defeat of American Brian Baker which gave him a place in the quarters at the St Jakobshalle.
The second-seeded Argentine, who had already increased his qualification hopes for London by winning the Vienna title last weekend, was delighted to make it into the eight-man, season-ending event for the third time.
But he was also sympathetic to the plight of Rafael Nadal who had to withdraw from the World Tour Finals, which begin a week from Monday, as he continues to battle back from the knee injury which has kept him off tour since June.
Del Potro said he knows exactly how Nadal feels after his own wrist injury absence in 2010 saw his career suffer a worrying setback.
"I'm sad for Rafa, he's really trying in his comeback. But it's not easy after such a long time away. I had the same feeling with my wrist.
"We miss Rafa a lot on the Tour. He is one of the best players in history, he will come back strong.
"I'm sure it will be very soon. He will be ready to win a big event again, I know that he can play better than me when he makes his comeback, I wish all the best to him."
Two Frenchmen also celebrated wins, with Paul-Henri Mathieu overcoming Russian veteran Nikolay Davydenko 6-3, 6-7 (2-7), 6-4 and Benoit Paire lining up a quarter-final date with Roger Federer after his 6-4, 6-4 defeat of Lukasz Kubot.
The 23-year-old Paire is buoyed by being at his highest ranking of 46 and fresh from an upset of fifth seed Andreas Seppi in the first round.
"I played a good match against Kubot, I'm very satisfied," said Paire, who admits that he has been working to curb his notorious temper.
"I've always admired Roger. It is a dream to be able to play him in his home. Of course he will be the favourite, but I want to put in my best effort and play as well as I can."
Paire nudged his 2012 record to 25 wins against 24 losses as he took down Kubot.
The Frenchman overcame the Pole in just under 90 minutes with six aces and three breaks of serve.
"It's great to be in a quarter-final and to be playing Roger Federer," added the Frenchman.
"I had a good match against Kubot which gives me confidence. And of course beating Seppi may have been a surprise.
"Federer had a tough time playing (Thomaz) Bellucci in the second round, it went to three sets. Anything is possible in tennis and I have my chances if things go well for me."
AFPTags: tennis, sport, switzerland, australia, argentina First posted October 26, 2012 07:11:50