Italian pair Francesca Schiavone and Flavia Pennetta upset Venus and Serena Williams in a challenge match in Milan on Saturday. The Italians triumphed 3-2 in the Fed Cup-style match that was played only over tie-breaks. Schiavone, the 2010 French Open winner, beat both Williams sisters in her singles matches while Pennetta beat Venus but lost to Serena. However, in the eagerly-anticipated doubles contest it was the Olympic champion Williams sisters -- who have 20 Grand Slam singles titles between them, 12 doubles titles together and four mixed doubles titles -- who came from a set down to win.