STRASBOURG, France - Second-seeded Jelena Jankovic advanced to the quarterfinals of the Strasbourg International with a 6-3, 6-3 win over Zheng Saisai on Tuesday.

In a match that featured 11 breaks of serve, the 30-year-old Jankovic proved more consistent and came through to line up a match with Sloane Stephens in the clay-court tournament.

"I'm looking forward to it. Every match is good ahead of the French Open and I'm playing well and I'll just try to keep it going," Stephens said.

A former No. 1, Jankovic has dropped to 25th in the WTA rankings, while Stephens made her breakthrough two seasons ago by reaching the semifinals at the Australian Open.

Before Strasbourg, Stephens had won just two matches on clay this year. But the 22-year-old player lost only five points on her first serve and broke once in each set to seal a 6-3, 6-4 win over sixth-seeded Coco Vandeweghe in an all-American match.

"I played a solid match, I was happy with that — it's always tough playing an American — and happy to get the win," the 41st-ranked Stephens said. Third-seeded Samantha Stosur also progressed to the quarterfinals with a walkover after opponent Lesia Tsurenko withdrew with a back injury.

Stosur, a former finalist at the French Open, will next play Ajla Tomljanovic, who defeated Shelby Rogers 7-6 (6), 3-6, 6-2.