Henin feels her way back to form and fitness in Srebotnik test

Jankovic during her laboured 4-6, 6-3, 6-4 win over India's Sania Mirza in the Dubai Tennis Championships (Reuters)

Wins for Justine Henin here are as commonplace as camels in the desert, but the world No 1 had particular reason to savour her victory last night over Katarina Srebotnik in the second round of the Barclays Dubai Championships. Although she needed three hours to overcome one of the game's journeywomen, Henin felt she found her best form of the year during her 7-5, 6-7, 6-3 victory.

The 25-year-old Belgian, who has won all 17 matches she has played here, dominated 2007 but has been suffering from a recurrent knee injury which almost forced her to withdraw from the Australian Open. After losing to Maria Sharapova in the quarter-finals in Melbourne – her earliest exit from a Grand Slam event for nearly three years – Henin had to have a cortisone injection in her right knee. Despite making a winning return in Antwerp earlier this month, Henin arrived here knowing that she was considerably short of her usual fitness levels.

Srebotnik, ranked No 28 in the world, showed plenty of spirit and in the first two sets regularly wore Henin down with her sheer persistence. The 26-year-old Slovenian won the second set tie-break 8-6 despite having trailed 5-3. Henin was in minor trouble when serving at 2-2 and 15-40 in the final set, but then turned on the style to earn a quarter-final meeting with Italy's Francesca Schiavone.

"That was the kind of match I need," Henin said afterwards. "Coming from playing indoors in Antwerp to playing outdoors isn't easy and to play Srebotnik in the first round was really tough. She's a good player. In the third set I felt the best I've felt on court for the last few weeks. It was a long match but it was probably what I needed. I volleyed quite well and I thought I served very well. My return was quite a problem in the first two sets, but I felt very comfortable in the third set.

"It was the first set this season in which I've enjoyed my game. I was moving forward, going into the net, serving better, returning better. I was glad I had the third set to find my rhythm. I've worked harder in the last few days than I normally would do before this tournament.

"I have to move forward now. I feel that I've only just recovered from everything that happened in 2007. Mentally and emotionally, I was pretty tired in Australia. Today I really enjoyed being out there, even if I wasn't perfect."

Henin said she had no major worries about her knee injury. "I have a cartilage problem and I have tendinitis. That's why I didn't play in Australia in 2005. At the beginning of the season, after my winter preparation, I always get this pain in my knee. We have to control that. I have to do a lot of exercises. I have a physio travelling all the time with me now. The knee is good now, but we have to work on it every day."

Ana Ivanovic and Jelena Jankovic have also arrived here in less than full health, but both Serbs are through to the last eight. Ivanovic, who withdrew from the Qatar Open last week with a foot injury, dropped only four games in beating Nicole Vaidisova to earn a quarter-final against Elena Dementieva, but Jankovic gave a laboured performance in beating India's Sania Mirza 4-6, 6-3, 6-4.

Jankovic suffered a series of injuries in Australia last month, her pre-season preparations having been hampered when she was laid up for a month following sinus surgery. Having previously been coached by her father, she is now working with an American, Scott Humphries, though his long-term job prospects do not sound hopeful.

"I'm in a trial period with him and I'm having a really hard time," Jankovic said. "I'm not used to practising like this. Everything is different. I'm trying to practise the way I used to last year, but he has a completely different way of doing things, so we need time. I'll know in a week or so whether we will continue to work together or whether I will look for a new coach."

Jankovic looked lethargic, served erratically and sprayed mishits all around the court. In the third set Mirza had three points for a 5-3 lead but wasted them with unforced errors as Jankovic's greater experience told.

"For some reason I feel tired," Jankovic said. "It's not as though I've been playing a lot of matches, but I don't feel that I'm moving very well on the court. I'm really struggling. There are some shots that I can usually make without much effort, but now I'm struggling to get those balls."

Jankovic now plays Anna Chakvetadze, with the winner to face Svetlana Kuznetsova or Amélie Mauresmo. Kuznetsova, the world No 3, dropped only three games to Lucie Safarova, but Mauresmo gave a patchy performance before overcoming Japan's Akiko Morigami 4-6, 6-1, 6-4.

Little has gone right for Mauresmo since she underwent an appendectomy 11 months ago and this week she fell to No 29 in the world rankings, her lowest position for nine years. "I don't really think seriously about retiring, but sometimes it does go through your mind," she admitted yesterday. "Deep inside of me I know that I want to keep going and try to get better again.

"The most important thing for me now is to keep the momentum going. Physically, I'm just happy to play a match every day. It's easy to lose the habit of playing. The win was more important today than the way I played. I started pretty badly. I was making too many unforced errors."