Justine Henin of Belgium holds the trophy after winning the final against Maria Sharapova of Russia at the WTA Championships tennis tournament in Madrid yesterday. - Reuters

MADRID, SPAIN (Reuters)

Despite crowning a dream season by retaining her WTA Championships title in a thrilling come-back victory against Maria Sharapova, Justine Henin believes there is plenty of room for improvement in her game.

"I think I can still improve a lot, in my attitude especially," the 25-year-old Belgian said after her dramatic 5-7, 7-5, 6-3 victory over the Russian at the Madrid Arena.

"I wouldn't say I played my best tennis, I was just fighting a lot. I played with my heart and it was great because that brings a lot of emotions. But I have to keep improving my aggressive game, moving forward and taking my opportunities."

The world number one was edged out by Sharapova in the first set as she experienced problems on her serve and struggled to cope with her opponent's powerful ground strokes.

She hit back in the second and then found another gear in the third to clinch a thrilling victory in three hours 24 minutes.

"What a way to finish the season; it is the best I could dream of. A lot of things happened but I'm so relieved and happy," she said.

Henin claimed nine other titles, including grand slam victories in France and the U.S. Open, and ended the year on a 25-match winning streak after she became the first woman since Steffi Graf in 1989 to go undefeated in the second half of the season, post Wimbledon.

She said her sights were now set on reclaiming the Australian Open title she won in 2004 after missing this year's tournament because of personal problems following her separation from her husband.

"I was sad I wasn't in Australia this year and I hope to take my revenge in a few weeks," she said. "It's time now for a good rest, time for holiday and two weeks off and then I'll start my preparations."