Sunday's WTA Tour round-up

Venus Williams retired from the final of the Warsaw Cup in the third set to hand victory to Amelie Mauresmo.

Top seed Williams was trailing 3-0 in the decider when she withdrew with a pulled stomach muscle, and she has pulled out of next week's German Open.

The American had won the first-set tiebreak 8-6 but failed to win a game as Mauresmo claimed the second set 6-0.

Williams then left the court for treatment and looked in great discomfort as Mauresmo took a 3-0 lead in the third set.

And after hitting her 13th double-fault to go 30-40 down in the next game, Williams retired.

"I felt it in the first set, but I didn't realise what it was," said Williams, who admitted she would be a doubt for next week's German Open.

"I thought it was a stomach ache. When I have an injury in the middle of a match I just don't believe it's happening to me.

"When I come back to reality I know I have to re-evaluate the situation and try and get some help if I can."

It was world number seven Mauresmo's first victory over Williams in six meetings.

"Even though I lost the first set I knew I was giving her some trouble and playing some good tennis," said Mauresmo.

"I just wanted to keep playing the same game, and that's what I did. I wanted to make her play as many shots as I could.

"On this surface, being slow, I knew that her pace wouldn't give me as much trouble as maybe on another surface, and I wanted to take advantage of this."

Despite the loss, Williams is set to regain her number two world ranking from Belgium's Kim Clijsters, who did not compete this week.

Russia's Vera Zvonareva claimed her first career title with a 6-1 6-3 victory over Conchita Martinez Granados.

The 18-year-old third seed kept Martinez Granados at bay with fierce and precise baseline shots and a solid serve.

"I didn't expect anything at the beginning of the tournament and kept telling myself I should just try and play my best tennis and show what I can do," said Zvonareva.

Martinez Granados, playing in her first career final, lost three games in the middle of the first set and had to seek medical attention for a sore shoulder after losing it 6-1.

The Spaniard came back from 1-3 down in the second to level at 3-3 but world number 28 Zvonareva staved off three game points before wrapping up the match.