Justine Henin's comeback was snapped as Gisela Dulko ousted the former world number one from the second round of the Indian Wells tennis tournament on Friday.

China's Li Na, ranked 10th in the world and seeded seventh, also bowed out after losing to British qualifier Elena Baltacha 7-6(6), 2-6, 7-6(7).

Henin, who retired in May, 2008, while No. 1 in the world, had reached the finals at Brisbane, Australia, and in the Australian Open in her previous tournaments since her comeback. But against Argentine Dulko, the 31st seed, the Belgian struggled on serve, saving just 2 of 8 break points.

"It was a tough day today, I agree," said Henin. "I was never into a good rhythm and never really found my way to win. Even in the second set it was better, but still a lot of ups and downs.

"She was playing quite high balls, also, and I never really found a good timing. So I wasn't consistent enough. That's very simple. It's a bit of an off day and you have to deal with it," she said.

Baltacha, ranked 65th in the world, notched her first victory over a top-10 player despite falling behind 5-1 in the third-set tiebreaker.

Li was part of an historic Chinese showing at the Australian Open, where both she and compatriot Zheng Jie made the semifinals.

It was after that performance that she made her career top 10 debut on February 17, the first Chinese player to claim a top-10 ranking.

Last month she reached the quarterfinals at Dubai, but retired from her quarterfinal against Shahar Peer with a back injury.

Baltacha, who came through two qualifying matches as well as a first-round contest, said she thought the first-round bye given to all 32 seeded players might have made things harder for Li.

"I think sometimes with the top players, the best time to play them is when they haven't played a match and for them it is the first round, because they haven't experienced the conditions, they haven't experienced the court, and it can be a bit tricky for them," she said.

Her remarks proved reasonable when some other top players had ups and downs in their first match on the same day.

Denmark's Caroline Wozniacki was 4-1 down in the third set before overcoming American Vania King 5-7, 6-2, 6-4 to progress to the third round while Elena Dementieva, seeded fourth, was also extended to three sets before the Russian downed Olga Govortsova of Belarus 6-4, 4-6, 6-0.

Maria Sharapova, seeded tenth, was another title contender forced to fight hard in the second round, overcoming Russian compatriot Vera Dushevina 4-6, 7-5, 6-2.

Other winning seeds include No. 5 Agnieszka Radwanska, No. 11 Marion Bartoli, No. 12 Maria Kirilenko, No. 15 Francesca Schiavone, No. 16 Nadia Petrova, No. 18 Zheng and No. 19 Aravane Rezai.

In the men's draw, first-round play involving unseeded players continued, with Argentina's David Nalbandian and American James Blake among the winners.