Clijsters through to Miami quarterfinals

MIAMI, March 29 (UPI) -- Second-seeded Kim Clijsters gained the quarterfinals of the Sony Ericsson Open Tuesday with a rain-delayed victory over former world No. 1 Ana Ivanovic.

Clijsters used a pair of tiebreakers to sneak past Ivanovic in three sets, 7-6 (7-4), 3-6, 7-6 (7-5), in a match that had been postponed from Monday in Miami.

The Belgian will next face eighth-seeded Victoria Azarenka in the quarters, which got under way Tuesday with a 2-6, 6-2, 6-4 upset victory by Andrea Petkovic over sixth-seeded Jelena Jankovic.

Petkovic, who knocked out top-seeded Caroline Wozniacki Monday, was the first to make it to semifinals, where she will face either 16th-seeded Maria Sharapova or Alexandra Dulgheru.