BRISBANE, Australia(AP) Ana Ivanovic advanced to the Brisbane International semifinals and a possible showdown against Justine Henin with a 6-4, 7-6 (6) win over Anastasia Pavlyuchenkova on Thursday.

The 2008 French Open champion, playing her first tournament since September, led by a set and 4-0 before her serve misfired and her unforced errors mounted.

Pavlyuchenkova, an 18-year-old Russian who is ranked No. 40, won six of the next seven games but was broken while serving for the set, a double-fault forcing the tiebreaker.

She raced to a 4-1 lead in the tiebreaker and had set point at 6-5, but committed errors on the next three points to surrender the match.

Third-seeded Ivanovic, who had work through tough three-set matches in the earlier rounds, was relieved to get through in straight sets.

Yeah, I like to do that to myself!'' Ivanovic joked about her lapses in the second set.I played really well from the first game and was up a couple of breaks in the second, and I relaxed a little bit. Intensity dropped.

``She picked it up ... I just had to stay tough and just stay in that second set. I'm happy to pull through that, and win in two.''

Fourth-seeded Daniela Hantuchova of Slovakia went out in straight sets, losing 6-4, 6-2 to 20-year-old German Andrea Petkovic in another quarterfinal.

The 22-year-old Ivanovic credited boyfriend Adam Scott, who has been as high as No. 3 in the world golf rankings, for helping her learn to keep calm.

``I get very emotional on court and I have highs and lows. That's something I've learned from him, to be more patient and just to be more in control of what's happening out there.

``Still, I get excited. There's a lot of adrenalin when it's close. And when it's second set, tiebreaker. I just let myself go sometimes.''

Henin was to play seventh-seeded Melinda Czink on Thursday, with the winner meeting Ivanovic in the semis.

This is Henin's first official tournament in her comeback. She retired in May 2008 when she held the No. 1 ranking, so is playing in Brisbane and Sydney on wild-card entries ahead of the Australian Open, which starts Jan. 18.

The 27-year-old Henin announced her comeback in September, soon after fellow Belgian Kim Clijsters won the U.S. Open only three tournaments into a comeback from retirement.

The Belgians could meet in the Brisbane final, with Clijsters playing a quarterfinal against Czech player Lucie Safarova on Thursday night. The winner of that will play Petkovic in the semis.