Belgian comeback queen Kim Clijsters knocked out Serena Williams in a wildly controversial finish on Saturday to advance to the final of the US Open and become the poster girl for working mothers.
Just weeks after returning to the tour from a two-year break to start a family, Clijsters beat the defending champion 6-4 7-5 after a day-long rain delay at Flushing Meadows.
In the men's competition Argentina's Juan Martin Del Potro bludgeoned Rafael Nadal 6-2 6-2 6-2 yesterday to reach his first grand slam final.
At 5-6, 15-30 down in the second set, Williams whacked her second serve but the lineswoman called her on a foot-fault that put her at match point down.
The American's subsequent expletive-laced tirade directed at the lineswoman resulted in a point penalty - and the end of the match.
"I swear to God I'm... going to take this... ball and shove it down your... throat, you hear that? I swear to God," Williams said.
After the line-judge reported the second seed to the umpire for verbal abuse, Williams added: "I never said I would kill you, are you serious?"
In last night's final, Clijsters was playing Danish teenager Caroline Wozniacki, who defeated unseeded and error-prone Belgian Yanina Wickmayer 6-3 6-3 in the other semi-final.
Del Potro on top
Del Potro, the sixth seed, overpowered Nadal in two hours, 20 minutes of outstanding hitting to set up a final against either five-times champion Roger Federer or fourth seed Novak Djokovic of Serbia.
The first set was a story of missed opportunities as Nadal squandered three break point chances, while the Argentine broke twice, in the fourth and eighth games.
The pattern was repeated in the second set and though Nadal continued to fight in the third, Del Potro was too strong and cruised to a comprehensive victory.
"It's very difficult for me to speak at this moment. This is my favourite tournament and I can't believe this moment," a beaming Del Potro said in a courtside interview.
"I am very close to my dream, to win this tournament. I hope I can do it. I am very happy to be here. Tomorrow (today) I will fight until the final point, if I win or lose, I think this is the best moment of my life."