Pierce ends injury absence with rusty San Diego win

Defending champion Mary Pierce was made to struggle in her first competitive match for six months before progressing to the third round of the Acura Classic in San Diego.

The 31-year-old sixth seed, who has not played since February after tearing ligaments in her foot, edged past Austria's Sybille Bammer 6-1 6-7 7-6.

Third seed Nadia Petrova was not so fortunate in her first match in over two months when she was upset 6-3 6-7 6-2 by fellow Russian Anna Chakvetadze.

Top seed Kim Clijsters crushed Australia's Samantha Stosur 6-1 6-2 in the second round.

Pierce struggled with her form much of the day, throwing away three match points with forehand errors in the second set tiebreaker, which she lost 9-7.

But the two-times Grand Slam champion stood strong in the third set against the left-handed Austrian, mixing heavy blows from the baseline with occasional net rushes.

Petrova injured her hip prior to Roland Garros and has not played since her first-round exit there to Japan's Akiko Morigami and looked rusty against the 19-year-old Chakvetadze. The latter will play another teenager, Serbia's Ana Ivanovic, who destroyed American qualifier Amy Frazier 6-3 6-2.

Fourth seed Elena Dementieva took down American Ashley Harkleroad 6-2 6-2 and will face India's Sania Mirza, who upended Katarina Srebotnik 6-3 7-6.

Russia's Vera Zvonareva advanced when China's Peng Shuai retired with heat illness. Zvonareva will now face second seed Maria Sharapova.

Flavia Pennetta of Italy, seeded 12, overcame American Jamea Jackson 6-2 7-6 and will play eighth seed Martina Hingis.

It is the first time since the tournament began in 1984 there are no American women in the third round.

Lindsay Davenport and the Williams sisters withdrew before the event with injuries.