Sloane Stephens survived two tiebreakers to beat No. 31-seeded Petra Martic 7-6 (6), 7-6 (5) and advance to the fourth round at Melbourne Park.

The fifth-seeded Stephens, the 2017 U.S. Open champion, will next play Anastasia Pavlyuchenkova, who beat Aliaksandra Sasnovich 6-0, 6-3.