Nadal, Murray Advance in U.S. Open 2011 -- Roddick and Isner Falter [Tennis]

It was finally a sunny day in Queens, New York, but the sun didn't shine on male American tennis players at the U.S. Open.

Defending champion Rafael Nadal and fourth-seeded Andy Murray each won their quarter-final matches on Friday afternoon, setting up their third straight semi-final meeting in a Grand Slam event.

Andy Murray defeated hard-serving American John Isner 7-5 6-4 3-6 7-6, and finished off the match with 7-2 score in the fourth-set tiebreaker to reach the U.S. Open semi-finals.

Though Isner reached his first Grand Slam quarter-final, he was disappointed with his overall effort. The towering 26-year-old had 17 aces in the match, compared to Murray's 14.

Murray had 47 winners and 20 unforced errors, while Isner had 55 winners and 54 unforced errors. The Scottish star will attempt to win his first major against Nadal, who dismantled Andy Roddick 6-2 6-1 6-3 in under two hours.

Nadal had 22 forehand winners in the match, while Roddick failed to get even one, and only had one backhand winner. The Spaniard has yet to drop a set in the tournament.

It was another disappointing effort for Roddick, who has been battling a leg injury and received two leg rubdowns from a trainer during the match. His leg was certainly giving him problems on his serve.

It's a bad feeling. It's almost worse than competing, Roddick said after the match. You feel helpless.

First Lady Michelle Obama was on hand and sat next to Billie Jean King.