LEAD: Clijsters recovery run continues into Melbourne semis

By Bill Scott Jan 24, 2012, 6:07 GMT

Melbourne - Kim Clijsters took another huge step in the defence of the Australian Open title on Tuesday, with the Belgian knocking out top seed Caroline Wozniacki 6-3, 7-6 (7-4) and putting the women's number one ranking in play.

The 11th-seeded Clijsters denied her Danish opponent after Wozniacki mounted a fightback from a set and 5-2 down, eventually taking the second set into a tiebreaker,

Wozniacki's loss means that the top-ranked player for the past two seasons will be replaced, with number two Petra Kvitova, Victoria Azarenka and Maria Sharapova all in the chase, according to WTA calculations.

Wozniacki remains without a Grand Slam title. She lost as Clijsters pounded a winner into the open court to earn a final-four match with Azarenka.

Azaranka, the third-seed from Belarus fought through to win her 10th match of the season, securing a place in her second career Grand Slam semi-final with a 6-7 (0-6), 6-0, 6-2 defeat of Agnieszka Radwanska.

Clijsters had been working with her personal travelling physio in the past 48 hours since upsetting China's Li Na in a dramatic match where she rolled her ankle but was able to grit out the win.

'These are the moments that I need him the most,' the former number one said. 'He makes me really angry in the off-season when he works me so hard. But this is the reason that I have to do that.

'It lets me do my work on court.'

Clijsters said that even with her lead in the match 'it didn't feel like it.'

'I had to work very hard. Caroline is very consistent and she began to play more aggressive. I'm glad I didn't have to play three sets, it's so hot out there,' she said of 35 Celsius summer temperatures

Azarenka, the 22-year-old world number three from Belarus, won her 10th match in a row after taking the Sydney title.

The third seed need a massive turnaround after taking a 7-0 hammering in the first-set tiebreaker against the Polish eighth seed Radwanska. Azarenka then proceeded to reel off seven games in a row, levelling the sets at one apiece and earning a lead in the third.

She broke Radwanska for 3-1 in the third set to provide the margin for victory in a shade over two hours.

'We just cannot play two sets,' said the winner after posting her seventh victory from 10 matches in the series. 'We have to push it to the limit, run each other around out there.

'We both showed some great tennis. We both fought hard. I'm glad I could stay tough and finish the match.

'I'm a year older and a year wiser,' said Azarenka, who lost in the fourth round a year ago. 'I'm playing step-by-step, playing every point and giving the best I can. If you do that, the result will be the result.

'I'm happy to be in the semi-finals and able to give it all out there.'