BERLIN (AFP) - World number one Justine Henin admitted she is using the German Open to recover her flagging form ahead of next month's French Open after she suffered a heavy defeat by Serena Williams earlier this year.

Henin, 25, has picked up two WTA titles this year, but after bowing out early at the Australian Open in January, she was hammered 6-2, 6-0 at the quarter-finals of the Miami tournament in March by eventual champion Williams.

It was the heaviest defeat for a reigning world number one since Martina Hingis lost to Jelena Dokic by the same score at Wimbledon in 1999.

Henin then withdrew from last month's Charleston tournament with a knee injury and this is her first tour event back ahead of Roland Garros which starts on May 26.

And with seven Grand Slam titles to her name - including four at the French Open - the Belgian has high plans in Berlin.

"I have really needed these last few weeks off to get my form back and to make tennis my priority again," said the Belgian, who has a bye into the second round where she will play Yung-Jan Chan from Chinese Taipei.

"If I can get my confidence back anywhere, then it will be here.

"I have won this tournament three times, I am feeling confident and motivated and I am here with high hopes.

"It is such an important tournament to do well so close to the French Open."

Henin says she is looking forward to the Berlin tournament to recapture her focus, but gave a clear indication she is planning for her eventual retirement.

"It's very hard to find a balance between the sport and your personal life, it is possible, but it is not easy, especially for those people around you," she said.

"I am making plans for the future, but I would like to go back and finish my high school qualifications and do other things like ski and travel once when I retire.

"I don't know what is going to happen in my career, but it is important to make plans.

"Things aren't the same as when I was 20, the body doesn't recover as quickly and it's all part of growing up.

"I'd like to play on for another two, three, maybe four years.

"But it is impossible to say how long I will play on for, you never know what is going to happen."

Late on Monday afternoon, France's Amelie Mauresmo withdrew from her first round game on Tuesday against compatriot Aravane Rezai with an injury to her intercostal muscles.

The 2006 German Open winner Nadia Petrova made it into the second round with a hard-fought win over Katarina Srebotnik.

But French starlet Tatiana Golovin was a first-round casualty when she was beaten by Denmark's Caroline Wozniacki in straight sets.

The 20-year-old had surgery at the start of last month to remove a cyst which was causing her back pain and she was making her return in Berlin after a 10-week break.

"I normally love playing in Germany, but it is just too soon to expect too much," said the Moscow-born Golovin.

"I only just had surgery and I am still recovering from that, I am not perfect yet and I'll need to take my time to recover my form.

"This is all just part of the process."

In the day's other key first round results, 15th seed Alona Bonderenko from the Ukraine beat Slovakia's Dominika Cibulkova, while Israel's Shahar Peer, 14th seed was beaten by Germany's Sabine Lisicki.