BANGKOK (AFP) - The leading trio of seeds each had to overcome niggles to achieve victories but Roger Federer, Andy Roddick and Marat Safin all managed to reach the quarter-finals at the 550,000-dollar Thailand Open.
Federer slipped briefly while serving for a 6-1, 6-3 victory against Swiss compatriot Ivo Heuberger; Roddick needed three sets to overcome Jeff Morrison 6-2, 6-7 (4-7), 6-4; and Safin wasted seven match points before ultimately securing his 6-3, 6-4 win against Jiri Vanek.
In contrast Thai Paradorn Srichaphan, seeded fourth, was untroubled in an easy second-round victory at the Impact arena as he hammered it out for the last place over Alex Bogomolov, 6-0, 7-6 (7-4) in a crowd-pleaser for the home fans.
Victories from all of the leading four set up a dream set of quarter-finals for the second edition of the tournament.
Federer, untouchable so far this season with the position of world number one already wrapped up and nine titles in his pocket, profited from the toothache torment of opponent Hueberger.
Federer showed no mercy once he found a chink in the armour of his outclassed Davis Cup compatriot.
"I knew Ivo has a tooth problem, and I took advantage of that," said this year's treble Grand Slam champion. "To have a chance against me you have to feel 100 percent right now."
Federer pronounced himself pleased with his sparkling form ahead of a Friday match 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 for it from a 6-1, 5-1 position of strength.
The 129th-ranked Heuberger saved three match points before going out.
Roddick needed to win a battle against fellow American Morrison in an entertaining struggle lasting for nearly two hours. "We both had fun out there," said the winner, making his Bangkok debut.
"I missed couple of easy shots in the second set, but the result eventually came up a win. We both appreciated competing hard, there were some good points.
"There was a huge (sellout) crowd, it was exciting." Roddick earned the win in just under two hours on his seventh match point.
Safin continued his roll in Asia after winning a title in Beijing this month.
"It just wasn't a good day for me to finish it off," said the winner of eight consecutive matches in the region and champion in Beijing.
"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.