Nadal, Murray march into last-four phase

Nadal, Murray march into last-four phase

Roddick, Isner bow out in quarters

"It's good for tennis," said Murray. "That's probably what people would like to see."

Andy Roddick and John Isner may disagree. Roddick was ripped apart by a ruthless Nadal 6-2, 6-1, 6-3 in less than two hours while the towering Isner finally ran into someone who could blunt his powerful serve, losing 7-5, 6-4, 3-6, 7-6 to Murray.

"I didn't have a lot of fun today," said Roddick.

The winners have little time to celebrate.

Nadal and Murray will be back on center court for their match on Saturday afternoon as part of a jam-packed day of four semi-finals forced by heavy rain during the week.

Djokovic and Federer, who had the day off after winning their quarter-finals on Thursday, will lock horns in the other men's semi-final, while Serena Williams will meet world number one Caroline Wozniacki in the women's last four.

The latter two will meet either Australia's Sam Stosur or unseeded German Angelique Kerber. Their semi-final has been moved from the center court to the Grandstand, one of the smallest showcourts, because of the increased schedule and leakage problems at Louis Armstrong Stadium.

Nadal may have been struggling with his form and confidence for the past few months but the defending champion showed he has lost none of his ruthless ambition against Roddick, who was battling a leg injury and a superior opponent.

The Spaniard seized control from the outset, winning the first four games, and broke Roddick's serve six times.

"Even if I lose tomorrow, I am happy about my U.S. Open," Nadal said. "It wasn't an easy situation for me coming to this tournament after not having an easy summer.

"I am doing a lot of things much better than few weeks ago. For me, a win is important but to feel competitive and have the feeling that I can win is probably even more important."

Murray was less convincing against Isner but the 6ft 9in (2.06m) American provided a much stiffer test than his countryman.

He took a set off Murray and pushed the fourth to a tiebreak. Isner had played six tiebreaks in the tournament and won them all, but Murray had other ideas.

"When he's serving you have no option other than to just try and get yourself in the rallies," the Scotsman said.

"You're under a lot of pressure on your own service games, so you don't want to just be rash and start trying to make huge winners or do anything stupid."

There was minor consolation for the U.S. when the teenage pairing of Melanie Oudin and Jack Sock won the mixed doubles final.

The pair, among a crop of the next generation of American players, needed a wildcard to get into the event but vindicated their inclusion by winning the final against the Argentine pairing of Gisela Dulko [ Images ] and Eduardo Schwank, taking the deciding tiebreaker 10-8 splitting the sets 7-6 4-6.