Australia's Daria Gavrilova has been sent packing from the St Pertersburg Trophy tournament in straight sets by Russian third seed Svetlana Kuznetsova.
Kuznetsova defeated the Australian 6-1 6-3 to extend her unbeaten record against Gavrilova to four straight matches and move into the quarter-finals.
Gavrilova was unable to make much headway on the Kuznetsova serve throughout the match and only managed three break points chances, while her opponent had ten against the Gavrilova and took four of them in a consumate display.
The win means Kuznetsova will face unseeded Kazakh Yulia Putintseva in the last eight, after she beat German Annika Beck 6-4 6-0.
Top seed Simona Halep made the quarter-finals by beating Ana Konjuh in straight sets.
The Romanian, who suffered a shock first-round defeat at the Australian Open, took 97 minutes to see off the world No.39 with a comfortable 6-4 7-6 (7-2) victory.
Halep has struggled with a knee injury in the early parts of the season, but felt no ill-effects following the win, which sets up a clash with local wildcard Natalia Vikhlyantseva after her 7-6 (7-4) 6-2 victory over eighth seed Daria Kasatkina.
"I didn't feel the pain today," a happy Halep said post-match.
"I'm really happy about that. I still want to wait for a few more matches to see how I feel. But now I'm feeling well."
Halep struggled at the beginning of the second set, going down 3-1 to the 19-year-old, but she was happy with her overall performance.
"I think it was a good match for me. I played much better than three weeks ago in Australia," she said.
"I feel better, more confident. I expected a tough match, because she has strong shots. I just tried to play my game and I think I did it pretty well finishing the match in two sets.
