Caroline Wozniacki beat a limping Dominika Cibulkova to reach Kremlin Cup semi-finals

Wozniacki wasted a couple of chances to end the match earlier and she was also aided by an ankle injury Cibulkova suffered in going down 6-2 6-7 6-1.

The former world No 1 looked in imperious form in the opening set, breaking Cibulkova's serve on a couple of occasions to take the upper hand.

She served for the match at 5-4 and 6-5 up in the second set but had her serve broken by the Slovakian player on both occasions and Cibulkova took the resulting tie-break with ease.

Wozniacki led 2-1 in the decider when Cibulkova, already sporting a bandage on her hip, needed treatment on an ankle injury, and she failed to win another game after the time-out to exit the tournament in disappointing fashion.

"It was a very good match today as both of us played very well," Wozniacki said.

"The difference at the end was that I just could keep my highest level up to the end and I managed to win most of the important points especially at the beginning of the third set."

She now faces Sweden's Sofia Arvidsson after her 6-3 6-3 win over seventh seed Maria Kirilenko, who was the last Russian left in either the men's or women's draw.

The other semi-final will see top seed Samantha Stosur take on another former world No 1, Ana Ivanovic, after both claimed straight-sets wins on Friday.

Stosur claimed a simple 6-1 6-3 success against Klara Zakopalova while Ivanovic had nop problems seeing off Vesna Dolonc 6-4 6-1 in an all-Serbian clash.