Roger Taylor beats Marin Cilic in four sets in U.S. Open third round . Federer survives upset as Croatian takes second seed at Flushing Meadows . Top seed Novak Djokovic also reaches fourth round after defeating Nikolay Davydenko . Ninth seed Tomas Beck forced to quit with a shoulder injury in New York .
Roger Federer beats Marin Cilic in four sets in U.S. Open third round . Federer survives scare as Croatian takes second set at Flushing Meadows . Top seed Novak Djokovic also reaches fourth round after beating Nikolay Davydenko . Ninth seed Tomas Berdych forced to quit with a shoulder injury in New York .