The defending champion Kim Clijsters is through to the semi finals of the Australian Tennis Open beating world number one Caroline Wozniacki in straights sets.
Clijsters won the first set 6-3 but had to work hard to win the second set 7-6 in a tiebreak.
The loss means Wozniacki, who's never won a grand slam title, will lose her number one world ranking.
Clijsters will play the world number three Victoria Azarenka in the semis.
Azarenka came back from a set down to beat Agnieszka Radwanska of Poland, 6-7, 6-0, 6-2.
