The 21-year-old Scotsman defeated the reigning Wimbledon, French Open and Olympic champion 6-2, 7-6 (7/5), 4-6, 6-4 in a match that began on Saturday but was concluded the next date after being halted by rain in the third set.

"I am delighted to be in my first Slam final," Murray said.

"I am delighted I won against a guy who has played as well as him. He is the best player in the world this year," he added.

The showdown with 12-time Grand Slam champion Federer was pushed to Monday, the first time since 1987 that bad weather has postponed the year's last Grand Slam tournament to an extra day.

Murray became only the third British man to reach a Slam final in the 40-year Open era, after Greg Rusedski in the 1997 US Open and John Lloyd at the 1977 Australian Open, and would be the first to win a title by beating Federer.

Murray owns a 2-1 lead over Federer in their career rivalry, losing their first meeting 6-3, 7-5 at the 2005 Bangkok final but winning 7-5, 6-4 at Cincinnati in 2006 and 6-7 (6/8), 6-3, 6-4 in Dubai six months ago.

Nadal carried a 19-match Slam win streak into his first US Open semi-final against a foe he had beaten in all five of their prior meetings, taking 11 sets in a row off Murray before Saturday.

Sixth seed Murray will rise to fourth in the next rankings, matching Tim Henman and Rusedski for the top ranking ever achieved by a British man.

Nadal held serve three more times to take the third set 27 minutes after the resumption, although he was pushed to a break point by Murray in the last game of the set before blasting three forehand winners to force a fourth set.

"I saw the match for sure was not impossible," Nadal said.
The drama grew in the second game of the fourth set when Murray, who saved a break point to hold in the prior game, squandered seven break chances and allowed Nadal to hold when Murray sent a forehand wide and netted a backhand.

On match point, Nadal tried a drop volley that Murray pounded with a backhand volley past the shocked Spanish left-hander to claim the greatest victory of his career after 90 minutes of play on Sunday and 3 1/2 hours overall.