Sloane Stephens has reached the third round of Wimbledon with a narrow three-set victory over Germany's Andrea Petkovic.

Both players struggled to hold serve during the opening set, but it was the American 17th seed who landed the first blow by taking the tie-break 7-2.

Petkovic, ranked 76th in the world, then opened up a 3-0 lead in the second before coming through 6-2.

However, Stephens earned herself a vital break in the decider which allowed her to clinch the victory 8-6.