Jelena Jankovic has been bundled out of the Sony Ericsson Open at the quarter-final stage by Andrea Petkovic while Kim Clijsters reached the last eight by beating Ana Ivanovic in a third-set tie-break.

22583 - Sharapova, Clijsters seal epic wins

No. 21 seed Petkovic is looking for just the second title of her career but she finds herself in the semi-finals in Miami after battling from a set down to take out world No. 7 Jankovic 2-6 6-2 6-4.

In a tight and tense match Petkovic won the points count 106-102, but she won the big moments when it mattered, saving nine break points and attacking Jankovic's second serve to secure the four breaks needed for victory.

In a day of classics, Maria Sharapova set up a semi-final clash with Petkovic by edging out Alexandra Dulgheru 3-6 7-6 7-6 despite serving up 17 double faults in the marathon three-hour, 29 minute clash.

Sharapova was broken an incredible 10 times across the match, including three each in the two sets she won in tie-breaks. But it was the type of encounter where every game was in the balance and Sharapova's return dominated Dulgheru's second serve, winning two thirds of points on those openings.

Meanwhile in the fourth round, Clijsters proved the stronger of two former world No. 1s as she edged out Ivanovic 7-6 3-6 7-6 despite losing the majority of the points across a tight match.

Service holds were a little easier to come by in this clash and the match therefore lasted more than an hour less than the Sharapova-Dulgheru epic, but it still stretched beyond two hours and Clijsters will look to her 11 double faults as an obvious area of improvement ahead of the quarter-finals.