Another upset served in the French Open: No. 1 seed Serena Williams lost to the seventh-seed Samantha Stosur at French Open quarterfinals Wednesday. Her sister Venus, who was the No. 2 seed, lost earlier in the tournament. On Tuesday, Robin Soderling upset Roger Federer in the quarterfinals, making it the first time since 2004 that Federer will not play in a Grand Slam semifinal round.