Justine Henin through to Brisbane international quarter-finals

Justine Henin overcame service problems to reach the quarter-finals in her comeback tournament with a 6-4, 6-3 win over Sesil Karatantcheva.

Henin dropped her opening service game and had to defend early against powerful groundstrokes from the Kazakhstan qualifier before taking control in the eighth game.

She dropped serve to start the second set and was only a point from falling behind 3-0 before she rallied to win five straight games for a 5-2 lead.

The seven-time Grand Slam champion was serving for the match when she was broken for the third time. But she broke back immediately, finishing with a forehand winner to advance to a meeting with seventh-seeded Melinda Czink.

Henin attributed the shaky start to the humidity and her first night match in a long time.

"I'm glad to play matches to find rhythm ... that's a very good thing," she said.

Earlier this week Henin beat second-seeded Nadia Petrova in her first match since May 2008, when she retired while holding the No 1 ranking.

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

The Belgians could meet in the Brisbane final in what would serve as an intriguing buildup to the Australian Open, which starts Jan 18 in Melbourne.

Clijsters will play a quarterfinal against Czech player Lucie Safarova, who had a 6-3, 6-1 win over sixth-seeded Aleksandra Wozniak of Canada on Wednesday.

Fourth-seeded Daniela Hantuchova of Slovakia beat Hungary's Agnes Szavay 6-3, 6-1. Anastasia Pavlyuchenkova of Russia will meet third-seeded Ana Ivanovic in the quarters after ousting Italy's Roberta Vinci 1-6, 6-4, 6-1.