(CNN) -- World number one Roger Federer fought off a tough challenge on Wednesday from Germany's Simon Greul to advance to the third round of the U.S. Open, while earlier Rafael Nadal knocked out a ruthless straight sets demolition of the returning Richard Gasquet.
Federer dispatched little-known Greul 6-3 7-5 7-5, and fired off eight aces. The top seed next faces Lleyton Hewitt, who cruised past Argentina's Juan Ignacio Chela.
Read more from original post: Federer fights off U.S. Open challenge; Nadal advances
