AMELIA ISLAND (Florida), April 11: Top seed Maria Sharapova needed more than three hours to beat Anabel Medina Garrigues and reach the Amelia Island Championship quarter-finals on Thursday.

Sharapova took a marathon three hours, 27 minutes to overcome Medina Garrigues 7-6, 5-7, 7-6 as both players slugged it out from the baseline.

Australian Open champion Sharapova joins fellow Grand Slam winner Amelie Mauresmo in the quarter-finals after the 11th-seeded Frenchwoman survived a first-set wobble to defeat Agnieszka Radwanska 3-6, 7-5, 7-6.

Sharapova, who had held a 5-3 lead in the final set but was rattled by a controversial line call in the ninth game, was struggling at 5-6 before she dominated her service game to force a tiebreak.

The tall Russian had no problems in the tiebreak, running through it 7-1.

Sharapova will meet 10th seed Alona Bondarenko, who also advanced with a three-set victory over sixth seed Dinara Safina, 7-6, 0-6, 7-5.

Mauresmo successfully landed 86 percent of her first serves in the opening set but her Polish opponent was able to record the only service break.

The 28-year-old Frenchwoman recovered in the second set and won the third-set tiebreak against the seventh-seeded Radwanska 8-6.

Mauresmo will face Slovakia’s Dominika Cibulkova, who upset second seed Anna Chakvetadze 6-2, 3-6, 6-1.

Cibulkova, who practised with Mauresmo last week in Miami, overcame early jitters and dominated the third set when she allowed her Russian opponent just 17 points.

Former world number one Lindsay Davenport, seeded 16th, also reached the last eight with a 6-4, 3-6, 6-4 win over Croatian Karolina Sprem.

Results (prefix number denotes seeding):

Third round:

Dominika Cibulkova (Slovakia) bt 2-Anna Chakvetadze (Russia) 6-2, 3-6, 6-1; 16-Lindsay Davenport (US) bt Karolina Sprem (Croatia) 6-4, 3-6, 6-4; 1-Maria Sharapova (Russia) bt Anabel Medina Garrigues (Spain) 7-6(3), 5-7, 7-6(1); 10-Alona Bondarenko (Ukraine) bt 6-Dinara Safina (Russia) 7-6(5), 0-6, 7-5; 11-Amelie Mauresmo (France) bt 7-Agnieszka Radwanska (Poland) 3-6, 7-5, 7-6(6); 8-Agnes Szavay (Hungary) bt 12-Katarina Srebotnik (Slovenia) 3-6, 6-2, 6-3; Alize Cornet (France) bt Elena Vesnina (Russia) 6-1, 7-5; 13-Virginie Razzano (France) bt Olga Govortsova (Belarus) 6-2, 6-4.—Reuters