Stuttgart, Germany :Justine Henin advanced to the quarter-finals of the Porsche Grand Prix and the path to her first title in her comeback was eased when top-seeded Caroline Wozniacki lost on Thursday.
Henin outlasted eighth-seeded Belgian teammate Yanina Wickmayer 6-3, 7-5. An ailing Wozniacki lost 6-4, 6-4 to Lucie Safarova of the Czech Republic.
Second-seeded Dinara Safina, playing her first match since retiring at the Australian Open in January with a lower-back injury, beat Agnes Szavay of Hungary 7-6 (5), 3-6, 6-0 to make the last eight.
Henin raced to a 5-1 lead in the second set and twice served for the match but could not finish it off. Wickmayer pulled even at 5-5 before Henin won the next two games.
"I got a little tight at the end," Henin said. "I was controlling the match but she came back. it wasn't easy to stay in the match."
Henin, a former longtime No. 1, has beaten Wickmayer both times they've played since Henin came out of retirement in January. Henin also beat her on the way to the final of the Australian Open.
Last week, the two were teammates on Belgium's Fed Cup team. Henin broke the little finger on her non-playing left hand while practicing for the Fed Cup and still wears a sling.
Wozniacki said she was still bothered by a right ankle injury, which she sustained at the Family Circle Cup in Charleston, South Carolina 10 days ago. The Danish player was forced to retire during her semi-final there.
"I didn't feel like I could move 100 percent," said Wozniacki, a U.S. Open runner-up last year. "And when you can't move, it's difficult to win."
Wozniacki had a bye in the first round.
Qualifier Anna Lapushchenkova of Russia produced another upset by ousting sixth-seeded Victoria Azarenka of Belarus 6-3, 6-3.
Fourth-seeded Jelena Jankovic of Serbia, the 2008 Stuttgart champion, eased past Tsvetana Pironkova of Bulgaria 6-2, 6-2.
"I am happy to get through," said Jankovic, who has a slight cold. She's seeking her second title of the year, following a win at Indian Wells.
Seventh-seeded Samantha Stosur of Australia rallied to beat Alexandra Dulgheru of Romania 3-6, 6-0, 6-2 for a place in the last eight, extending her winning streak on clay to nine.
Safarova, ranked No. 38, made her second quarterfinal of the year and said she could notice Wozniacki was struggling with the injury.
"I tried to make her run and to push her around," Safarova said. "I always need time to get used to clay but now I am playing better."
Safarova, whose first-round opponent _ Selima Sfar of Tunisia _ retired with an ankle injury, also served well, putting in 83 percent of her first serve and hitting five aces.
"She was making me run and that's why she won. I hate to lose but now it's important to get fit," Wozniacki said.
Stosur struggled against Dulgheru in the first set but was able to bounce back.
"She played a decent game, well enough," Stosur said. "I was frustrated but I tried to stay calm."