France's Paul-Henri Mathieu made up for last year's injury frustration here with a 6-3, 7-5 upset win over fifth seed Kenneth Carlsen to reach the quarter-finals of the ATP $400,000 Chennai Open on Thursday.
The 22-year-old Mathieu had to retire in the first round against the Danish left-hander in the 2003 event due to a wrist injury which sidelined him for seven months.
"This is where I got injured so it was satisfying today," Mathieu said.
The Frenchman, ranked 123rd in the world, next faces world number five and defending champion Carlos Moya, whom he beat during the Davis Cup semi-final defeat against Spain last year.
Kristof Vliegen of Belgium saved two match points to topple sixth seed Yen-Hsun Lu of Taipei 1-6, 7-5, 7-6 in a two-hour-and-15-minute duel to oust all but the top two seeds in singles.
The 116th-ranked Vliegen, 22, cleverly mixed his game to escape twice from 2-5 down as the 21-year-old Lu, regarded as a rising talent from Asia, completely choked.
"In the end, it was a mental game," said Vliegen, looking forward to a good year after drawing top-notch first-round rivals and suffering an ankle injury in 2004.
The Belgian next plays second seed Paradorn Srichaphan of Thailand, the 2003 winner, who outclassed Nicolas Devilder of France 6-3, 6-2.
