Pakistan, Aug. 13 -- World number two Elena Rybakina came from a set down to defeat four-time Grand Slam winner Naomi Osaka on Tuesday and reach the WTA Toronto Masters semi-finals, 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. It was a very difficult match," Rybakina said after a tight battle lasting 2hr 33min.

"In the first set (I made) a few mistakes, a poor start. "It was a really tough one but I'm glad I could turn it around, I don't yet know how, but I think my serve helped me a little bit." Gauff, a 22-year-old American, had a walkover into her first Canada semi-final when Switzerland's Belinda Bencic wit...