Rafael Nadal, the defending U.S. Open champion, continued with his good form with a 6-2 6-1 6-3 victory over Andy Roddick to set up a semifinal against Andy Murray.

Nadal, the world number two, appeared to be on a rush racing to a 4-0 lead in the first set. He never looked back, and broke Roddick three times in the second and once in the third.

While it was a highly impressive display from Nadal, Roddick appeared to be struggling physically in the latter stages.

Nadal took the first four games in 18 minutes.

The 10-time Grand Slam champion hit 35 winners which included 22 off his formidable forehand side.

Seeking his 11th Grand Slam title, Nadal is the only remaining men's player in the tournament who is yet to lose a set.

I'm sorry for him - he has had a fantastic career and it a great champion, Nadal said about Roddick.

Ahead to his meeting with Murray, Nadal added, It's always a pleasure to play Andy, he's one of the players with the most talent on the tour.

Nadal has won 12 of 16 matches against Murray. This will include defeating Murray in the semifinals of the French Open on clay and Wimbledon on grass this year.

The exits by Roddick and Isner mean that this will be another Grand Slam tournament without a male champion from the United States. The drought is continuing.