Top seed Vera Zvonareva was forced to retire from the WTA Pattaya Open in Thailand on Friday with a left hip injury.

The Russian, who won the title in 2009 and 2010, quit her quarter-final against seventh-seeded Romanian Sorana Cirstea after winning the first set 6-2, losing the second set 6-4 and at 2-2 in the third.

Defending champion and third-seeded Slovak Daniela Hantuchova won a high-quality battle against American eighth seed Vania King, advancing 7-6 (9-7) 6-4.

Fourth-seeded Russian Maria Kirilenko held off a strong first set challenge from Thailand’s Tamarine Tanasugarn before dominating the second to earn a 7-6 (7-2) 6-1 victory, and Taiwanese qualifier Hsieh Su-Wei reached her first WTA Tour semi-final in more than 10 years as she defeated India’s Sania Mirza 7-5, 6-3.

“It started bothering me already in the beginning of the first set, and it was getting worse and worse” said Zvonareva of her injury.

“I was doing my best, but it was too tough for me to push off from that leg and it was very difficult to focus on the game.

“I did everything I could but just couldn’t continue anymore.”

Zvonareva will now travel to her next event in Doha, but is still unsure whether she will be able to play.