Singapore: Garbine Muguruza reached the WTA Finals Last Four unbeaten on Friday after a tough win over Petra Kvitova — who also qualified for the semis with help from her fellow Czech Lucie Safarova.

Garbine Muguruza

On a rollercoaster last day of group play, Muguruza and Kvitova shared 15 service breaks in a see-sawing three-setter before the increasingly impressive Spaniard won 6-4, 4-6, 7-5.

Kvitova’s hopes were hanging by a thread but she went through when her friend and Fed Cup teammate Safarova beat Angelique Kerber 6-4, 6-3, stopping the German finishing second in White Group. Muguruza will play Agnieszka Radwanska in the semis while Kvitova will meet Maria Sharapova.