American teenager Sloane Stephens caused the biggest upset at this year's Australian Open when she overcome Serena Williams in the quarterfinals today.
19-year-old Stephens prevailed 3-6 7-5 6-4 to set up a semifinal against defending champion Victoria Azarenka
Earlier, Azarenka marched on with a 7 5 6 1 triumph over Svetlana Kuznetsova and in so-doing kept her grip on the number one ranking.
In the men's quarter-finals, third seed Andy Murray destroyed the unseeded Frenchman Jeremy Chardy 6 4 6 1 6 2 in 1hr 51min on Rod Laver Arena, and will now face either Roger Federer or Jo-Wilfried Tsonga in the semi-final on Friday.
