World number one Justine Henin struggled into the Australian Open third round with a 6-1 7-5 victory over Russian Olga Poutchkova.
After winning the first set in just 22 minutes, the Belgian top seed looked to be on the way to setting up a match against Italy's Francesca Schiavone in under an hour.
Russian Poutchkova, however, finally woke up and although she struggled to hold her own serve, she broke Henin three times in the second set and saved three match points before the Belgian wrapped up victory in 83 minutes.
'I was well into the match and played very aggressive and I did a good job in the first (set) ...then I lost a little bit of the intensity, a little bit of the rhythm on my serve,' Henin told reporters.
The tall Russian, who appeared lethargic in the first set, forced five break points in the first game of the second, though was unable to convert them as Henin battled back with her trademark powerful groundstrokes.
Poutchkova immediately lost serve but had her opponent in trouble again with three break points in the third game and a Henin double fault enabled her to convert one.
Neither player could hold serve before Henin established a 5-2 lead and the US Open champion had a match point in the next game, which she failed to convert.
The Russian saved two more match points in the tenth game and held serve to even the set at 5-5 before Henin held then made no mistake on her fourth match point opportunity when Poutchkova's backhand sailed over the baseline.
Champion Serena Williams rolled into the third round with a routine 6-3 6-1 win over Chinese qualifier Yuan Meng.
The seventh seed was well short of her best but still proved far too strong for the world number 121, easing to victory in 71 minutes.
As she had in her first-round match, Williams looked a little sluggish early on and Yuan's speed and excellent retrieving skills helped her to twice recover an early break.
But the American broke again in the eighth game before serving out for the opening set and cruised through the second to set up a meeting with 26th seed Victoria Azarenka of Belarus.
Elsewhere, third seed Jelena Jankovic used an injury time out to refocus her energy and reach the third round with a 6-2 7-5 victory over Romania's Edina Gallovits.
Jankovic, who took over three hours to dispatch Austria's Tamira Paszek in the first round, romped through the first set against Gallovits before suddenly looking out of sorts in the second.
The 22-year-old Serb flexed her right shoulder continuously throughout the early part of the set and took an injury time out to receive courtside treatment before the sixth game. The break allowed her to refocus her concentration and she levelled at 3-3.
Despite being broken when serving for the match at 5-4, Jankovic broke Gallovits again in the 11th game and served out to love in the next to complete victory in 91 minutes.
Selected women's results:
Aravane Rezai (France) bt 13-Tatiana Golovin (France) 6-3 3-6 6-3
12-Nicole Vaidisova (Czech Republic) bt Alicia Molik (Australia) 6-2 6-3
30-Virginie Razzano (France) bt Flavia Pennetta (Italy) 6-2 5-7 6-3
18-Amelie Mauresmo (France) bt Yaroslava Shvedova (Russia) 6-4 7-6 (7-5)
26-Victoria Azarenka (Belarus) bt Sandra Kloesel (Germany) 6-1 6-1
Casey Dellacqua (Australia) bt 15-Patty Schnyder (Switzerland) 4-6 7-5 8-6
25-Francesca Schiavone (Italy) bt Angelique Kerber (Germany) 6-2 6-3.
