Muguruza twists ankle, retires in Linz

Top seed Garbine Muguruza was forced to retire more than two and a half hours into her quarter-final clash with Viktorija Golubic at the Generali Ladies Linz on Friday.

The top-seeded Spaniard found herself in a real battle against the Swiss World No 62, and eventually retired hurt with the score locked at 7-5, 3-6, 4-4 in the third set.

After finding herself on the receiving end of a serious fightback from Golubic in the second set, Muguruza looked to be on course for victory as she opened up a 4-2 lead in the decider.

But the French Open champion fell badly in the seventh game, twisting her ankle, and after surrendering another break to Golubic she was forced to call it a day.

Golubic moves on to the semi-finals where she will face third seed Madison Keys, who continued her good form with a 6-3, 6-3 victory over Océane Dodin – although she admitted afterwards she wasn't at her best.

"I'm not feeling great, but I'm happy I got the win today," said Keys. "[Dodin] is a tough player, she can hit some really, really good shots."

The other semi-final will see fourth seed Carla Suarez Navarro of Spain take on second seed Slovakia's Domonika Cibulkova in a potentially exciting match-up.

Suarez Navarro survived a spirited challenge from Denisa Allertova to emerge a 6-4, 4-6 6-2 winner.

"I think I played really good at the end of the match," said Suárez Navarro. "I like the court – I like everything of the tournament."

Cibulkova, meanwhile, edged Anastasia Pavlyuchenkova 7-6 (7-3), 6-4.