World No. 2 Elena Rybakina came from a set down to defeat four-time Grand Slam winner Naomi Osaka on Tuesday to reach the WTA Toronto Masters semifinals, where she will face fourth-ranked Coco Gauff.

Rybakina, the reigning Australian Open champion from Kazakhstan, fired 13 aces in a 4-6, 7-6 (7-5), 6-4 victory.

“Super happy,“ Rybakina said after a tight battle that lasted 2 hours and 33 minutes. “It was a very difficult match.