The top seed Li Na and second seed Maria Sharapova both secured the semifinal berths at the WTA Birmingham tournament on Friday.

The Chinese top player Li resumed her unfinished last 16 match at 4-6, 6-3 on Friday, seeing off a spirited Angelique Kerber from Germany with a 7-5 victory in the decider.

Li played a much easier quarterfinal match later, defeating Kaia Kanepi from Estonia 6-4, 6-2.

Li's next opponent is French Aravane Rezai as the No. 4 seed won 7-6, 7-5 against Sarah Errani of Italy.

Russian master-hand Sharapova secured her place in the last four after a 6-2, 6-4 victory over qualifier Sesil Karatantcheva.

Sharapova is going to face American teenager Alison Riske who stunned the No. 3 seed Yanina Wickmayer of Belgium 6-7, 6-4, 6-3.