Wozniacki, Halep into Stuttgart semis

Stuttgart - Romania's Simona Halep will face Caroline Wozniacki in the semi-finals at the WTA tournament in Stuttgart after her straight-sets win over Italy's Sara Errani on Friday.

The 23-year-old Halep, ranked third in the world, needed just under an hour-and-a-half to seal a 6-4, 6-4 win over Errani in a tight quarter-final on the indoor clay court.

Halep finally converted her fourth match point and there were a total of 16 breaks in the 20 games.

"It was a tough game, she defended very well and it was hard to finish points off against her," said Halep.

"I'm looking forward to the semi-finals now."

Halep, the 2014 French Open finalist, now faces former world number one and boxing fan Wozniacki after the Dane floored Spain's Carla Suarez Navarro 6-0, 6-3 in just over an hour.

"I surprised myself by having fun out there today, I don't normally like clay, but it was nice to slide and run," said fourth-seed Wozniacki, who says she sometimes spars in training.

"I like to box from time to time, it's a great cardio work-out," added the 24-year-old.

Halep is the highest seeded player still in the event after reigning champion Maria Sharapova, who had won all of her three previous tournament appearances in Stuttgart, was beaten by Germany's Angelique Kerber on Thursday in the second round.

Results on Friday from the WTA Stuttgart tournament (x denotes seeding):

Quarter-finals

Simona Halep (ROM x2) bt Sara Errani (ITA) 6-4, 6-4

Caroline Wozniacki (DEN x4) bt Carla Suarez Navarro (ESP x8) 6-0, 6-3

Angelique Kerber (GER) bt Ekaterina Makarova (RUS x6) 6-3, 6-2

Madison Brengle (USA) bt Caroline Garcia (FRA) 3-6, 6-3, 6-3