Pattaya: Top seed Vera Zvonareva was forced to retire from the Pattaya Open 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.
But 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.
King's serve was broken as she served at 5-4 for the opening set against Hantuchova and although she then held a set point at 6-5 in the tiebreak Hantuchova edged it on her own second set point.
Three breaks in the second set left Hantuchova leading 3-2 against a tenacious opponent, and she moved on to a well-earned victory.
Hsieh last contested a semi-final in September 2001 when she was just 15, losing to eventual champion Angelique Widjaja in Bali, but then made little impression at the top level of the game, with a fourth round appearance at the 2008 Australian Open the only highlight.
She credits her current success to her coaching relationship with Paul McNamee, a former world number one doubles player and winner of two Australian Open and two Wimbledon men's doubles titles.
"We started at Wimbledon and for the US Open and he was helping me for doubles," she said. "Paul was helping an Australian girl at Wimbledon and she said maybe he could help me, and I didn't know who was this guy but said I'll give it a try.
"I reached the semi-finals at Wimbledon in mixed doubles and I think we work pretty well together. I understand what he is talking about."
Hsieh was broken in the third game and faced a set point at 5-4, but Mirza hit long and a double-fault then gave her a break point to level at 5-5.
After breaking again for the set, she went on to claim the second on her third match point.
"She worked very hard in Melbourne and deserves her success," said McNamee, who was impressed with Su-Wei when she competed at the Hopman Cup, where he is the tournament director. "I think it helps her having someone like me who believes in Su-Wei's unique talents."