BANGKOK (AFP) - Roger Federer bore down hard on the tooth ache torment of second-round opponent Ivo Hueberger, crushing his fellow Swiss 6-1, 6-3 to rip into the quarter-finals of the 550,000 US dollar Thailand Open.
After earning his 66th win of a superlative season, the runaway world number one revealed he'd found a chink in the armour of his outclassed Davis Cup compatriot, ranked 129th.
"I knew Ivo has a tooth problem, and I took advantage of that," said this year's three-time Grand Slam champion who has dominated the ATP with nine titles. "To have a chance against me you have to feel 100 percent right now."
After getting through all but unhindered -- save a late niggle which he quickly overcame -- Federer said he was pleased with his sparkling form as he prepares for a Friday quarter-final against Swedish eighth seed Robin Soderling.
"The match was good today, I was happy about my game," said the Swiss, who slipped briefly while serving from a 6-1, 5-1 position of strength.
At that point, Heuberger suddenly discovered a patch of form, saving a pair of match points and forcing his opponent to salvage two break points.
Heuberger kept up the pressure, holding Federer off on a third match point and finally taking the game as the top seed double-faulted for his only time in the 51-minute match.
Two games later, Federer put things right as he blasted over his sixth ace to claim victory on a fourth try.
"You just hang in there," said Federer. "That was the first tough game we'd had all match long. I would have liked to close it out, but I'm happy with 6-1, 6-3.
"I was pleased all the way through, even in the game I got broken. It was no problem to accept that. All in all, I'm very happy."
Third seed Marat Safin has had minor troubles, requiring eight match points and plenty of patience to finally shut down Czech Jiri Vanek 6-3, 6-4.
The Russian, who is on a roll in Asia after winning a title in Beijing this month -- the 12th of his career and first since 2002, finished his hard-fought job against the surprisingly difficult world number 130 in 74 minutes.
"It just wasn't a good day for me to finish it off," said the winner of eight consecutive matches in Asia who reached his sixth quarter-final of the season. "It happens."
"He was trying, he didn't lose any of his opportunities," said the Russian, now 36-18 this season. "He fought to the end and didn't give me any presents."
Safin moved into a match-up against Brazil's Flavio Saretta, who beat Rogier Wassen of the Netherlands in the second round, 3-6, 6-1, 6-2.
Defending champion Taylor Dent failed to follow on from 2003, going down to Dutchman Dennis van Scheppingen 6-0, 6-4.
"I've lost a lot of confidence recently," said Dent. "I've been spending three hours a day on the practise court. But the only way to gain confidence back is to win matches."
Sweden's Soderling marched into the last eight against Federer as he defeated Australian Paul Baccanello 6-1, 6-3. Compatriot Thomas Johansson defeated Adrian Garcia of Chile 6-3, 6-3.