Vaidisova to battle former idol Williams for place in final

As a budding 11-year-old player at Nick Bollettieri's academy in Florida, Nicole Vaidisova was always thrilled to watch Serena Williams practising.

Tomorrow the 17-year-old Czech takes on the 25-year-old American in competition for the first time, with a place in the Australian Open final at stake. In yesterday's quarter-finals Vaidisova, the world No 12, eased past her compatriot, Lucie Safarova, 6-1, 6-4, while Williams had a major struggle beating Shahar Peer 3-6, 6-2, 8-6.

Vaidisova, who insists she will not be overawed by her task, still describes herself as a fan of Williams. "I admired the way she played," she said. "I watched her practise at Bollettieri's and I was very excited to see her play. I was definitely very impressed with her."

Williams was within two points of defeat against Peer as she maintained her remarkable run. Playing only her seventh tournament in the last 16 months, the 2003 and 2005 champion here is now No 81 in the world. She described herself yesterday as "the ultimate competitor" and proved her point by holding her nerve just as Peer lost hers.

The men's singles semi-finals will feature a much more familiar confrontation. Roger Federer and Andy Roddick have played each other 13 times, the world No 1 winning on 12 occasions, including two Wimbledon finals and last year's US Open final.

They will meet again after their impressive wins yesterday. Federer, the defending champion, beat the Spaniard Tommy Robredo 6-3, 7-6, 7-5, while Roddick overcame his fellow American and former flatmate, Mardy Fish, 6-2, 6-2, 6-2.

Federer, who is now unbeaten in his last 34 matches, is through to a Grand Slam semi-final without dropping a set for the fourth time. It will be his 11th successive appearance in the last four of a major, beating Ivan Lendl's record for the Open era of 10.