We're still not quite sure why Victoria Azarenka left the court for so long in a controversial win over Sloane Stephens. We just know, it smells like gamesmanship.
Sloane Stevens, two months shy of her 20th birthday, appeared as stunned as anyone in the moments after upsetting third-seeded Serena Williams, who hadn't lost a match since late August.
After getting off to a fast start, it took American Sloane Stephens three sets to finally put away Serbia's Bojana Jovanovski 6-1, 3-6, 7-5.
Roger Federer took care of a wily veteran in Nikolay Davydenko. But the Swiss' real test now comes against a kid with a lot to prove.