Former No. 1 Ana Ivanovic ended 19-year-old American Sloane Stephens' run at the U.S. Open for the second consecutive year.

The 12th-seeded Ivanovic overcame 56 unforced errors, a deficit and a partisan crowd in Arthur Ashe Stadium to beat Stephens 6-7 (4), 6-4, 6-2 in the third round Saturday night.

Ivanovic eliminated Stephens at the same stage at Flushing Meadows in 2011.

Since winning the 2008 French Open — her third final in a stretch of five Grand Slam tournaments — Ivanovic hasn't reached the quarterfinals even once. She'll get a chance to get to the last eight in New York after taking the last four games against Stephens, who at No. 44 is the youngest member of the top 50 in the WTA rankings.

Next for Ivanovic is a fourth-round match against 55th-ranked Tsvetana Pironkova, who defeated Silvia Soler-Espinosa 6-1, 6-7 (3), 6-3.

"It's not going to be easy. But it's definitely a good chance for me; for her. It's great to be in a position to play for a quarterfinal," Ivanovic said. "Like I said before the tournament, it would be a big goal of mine. So I really want to put my head down and work hard for that match."

Stephens, who lives in Coral Springs, Fla., had 10 double-faults. She said afterward that she was bothered by a minor abdominal strain; she woke up Saturday with some swelling.

"It affected my serve, kind of threw me off a little bit," Stephens said. "Things like that happen. It's nothing you can control."