Top seed Jennifer Capriati is on course to win consecutive Australian Open crowns.
After two days of rain, the roof on the Rod Laver Arena was opened for the center court matches and Capriati says the outdoor atmosphere worked for her.
She breezed into the semi-finals by defeating Amelie Mauresmo from France in straight sets 6-2, 6-2.
"I was just really focussed and concentrated and just keeping my eye on the ball and not getting distracted and you know I had a mission and I played like I was on a mission," she said.
Capriati plays the French Open finalist, Kim Clijsters. Clijsters had a comfortable win over her Belgian compatriot, Justine Henin.
In the summer sunshine, a stomach injury cruelly put a stop to Wayne Ferreira's campaign here.
The South African's two previous marathon five-setters, obviously took its toll on his 30-year-old body.
He managed just seven games in the quarter final before retiring, with the 2000 U.S. Open Champion, Marat Safin, leading 5-2.
Safin will face the seventh seed, Germany's Tommy Haas, in Friday's semi-final.
Haas defeated the former World Number one, Marcello Rios, in four sets.