Roger Federer beat the final American left in the Western and Southern Open Friday night to advance to the semifinals.
Federer, a 4-time champion in Mason, beat Mardy Fish and now faces Stanislas Wawrinka in Saturday's semifinal. Juan Martin del Potro will play Novak Djokovic in the other semi.
Venus Williams also advanced, but her sister Serena lost in Friday's quarterfinal. It's Serena's first lost match since May.