Also gaining the quarter-finals was second-seeded Russian Svetlana Kuznetsova, the former U.S. Open champion who swept past German wild-card Martina Muller 6-1, 6-4.

In first-round matches, Iveta Benesova of the Czech Republic, who lost in qualifying but replaced an injured Ana Ivanovic in the draw, advanced when seventh-seeded Francesca Schiavone of Italy retired with a right wrist injury while trailing 6-3, 6-7 (5), 3-0, and eighth-seeded Jelena Jankovic of Serbia beat 1993 champion and two-time runner-up Mary Pierce of France 7-6 (7), 6-3.

Coming off a first-round bye, Dementieva had to rally from 6-4, 4-1 down before extending her perfect record against Srebotnik to 6-0.

Serving for the match at 5-4 in the third set, Dementieva slumped to the court clutching her left thigh. After receiving about five minutes of treatment, the Russian committed one of her 11 double faults and dropped her serve.

But she broke right back and then closed out the match with a forehand winner on her second match point.

``It was very tough to move for a time,'' Dementieva said. ``I really wanted to win and I did all I could. We both played very well.''

Kuznetsova, seeking her fourth title this year, broke Muller three times and won 30 of 34 points on her first serve.

A backhand error by Pierce gave Jankovic the first set. She quickly broke for 2-1 in the second and rode that advantage to clinch the match with a forehand winner.

Also in the first round, Tsvetana Pironkova of Bulgaria beat Karolina Sprem of Croatia 6-1, 6-4 in a showdown between two qualifiers, and Daniela Hantuchova of Slovakia defeated qualifier Sybille Bammer of Austria 6-3, 5-7, 6-3.