Pliskova into Toronto quarters; Venus, Kerber ousted
World number one Karolina Pliskova advanced to the quarter-finals of the WTA Toronto hardcourt tournament while Venus Williams and Angelique Kerber crashed out in straight sets Thursday. Pliskova's opponent Naomi Osaka abandoned due to a muscle injury, leaving Pliskova to advance 6-2, 6-7 (4/7), 1-0. Pliskova meanwhile was left satisfied after pounding down 12 aces and not dropping her serve once. But she admitted however that she faces a tough challenge holding on to her world number one ranking. "It's going to be tough," Pliskova said. "I'll do my best to stay there as long as I can -- hopefully a few more weeks." Elina Svitolina easily dispatched the 37-year-old Williams 6-2, 6-1 while American Sloane Stephens crushed two-time major championship winner Angelique Kerber by identical 6-2, 6-2 scores. Pliskova will now face former world number one Caroline Wozniacki in the last eight.