Murray aims to become the first British man since 1936 to win a Grand Slam
Britain's Andy Murray completed a sensational victory over world number one Rafael Nadal to reach his first Grand Slam final at the US Open.
The Scot, 21, resumed the rain delayed semi-final leading by two sets but trailing by a break, and Nadal soon cut the deficit by winning the third set.
But Murray recovered from a break down in the fourth set to beat the Spaniard 6-2 7-6 (7-5) 4-6 6-4.
He faces four-time defending champion Roger Federer in Monday's final.
Murray is aiming to become the first British man to win a Grand Slam singles title since Fred Perry won the US Open in 1936.
The final will take place a day late, at 2200 BST, after the rain disruption on Saturday that resulted in Murray being agonisingly halted, having won the first two sets.
It brought back memories of Murray's predecessor as British number one, Tim Henman, who famously lost a Wimbledon semi-final to Goran Ivanisevic in 2001 when rain seemingly stopped the home favourite in his tracks.
Murray has already equalled Henman by assuring himself of a world ranking of four after the tournament and he has matched Greg Rusedski's run to the US Open final in 1997.
But he has surely proved himself to be a greater talent than either of his compatriots with victory over the seemingly unbeatable Nadal.
The Spaniard came into the semi-final with a 5-0 record against Murray, having won the French Open, Wimbledon and the Olympic title in recent months and eyeing a first US Open crown.
It's awesome to beat him, a great feeling
Murray, in contrast, was playing his first Grand Slam semi and had to put a crushing defeat by Nadal at Wimbledon out of his mind.
He did so magnificently - and it was all the more impressive as he effectively had to win the match twice.
Murray had played superbly on Saturday to take charge on the Louis Armstrong Stadium, totally dominating on serve and breaking three times as he forged two sets clear before Nadal grabbed an early break in the third.
It seemed the rain might have come at the right time for Nadal and he began in much more positive fashion when play resumed on Sunday, with the match switched to the 23,000-seater Arthur Ashe Stadium.
Murray managed to earn one opportunity to get the break back in game 12 of the third set but Nadal fired down an ace before converting his second set point.
Both players hit the heights in the early stages of the fourth set but it was Murray who was keen to take the initiative.
After saving an early break point with an ace, the Scot fashioned seven chances to break in game two but Nadal just would not yield.
And having escaped from that crucial game he immediately broke Murray to love and appeared to be closing on a fifth set.
I did a good semi-final and when I arrived I had too many matches on my shoulders
But Murray remained undaunted and continued to press, breaking back at 3-3 as he dictated the rallies and forced errors from Nadal.
A place in the final was within sight now for the Briton and he shrugged off a missed break point in game eight, easily holding serve before setting about the Spaniard's serve again at 5-4.
Murray got a huge slice of luck with a net cord on the first point and at deuce he made his move, darting into the net to punch away a volley before chasing down a poor drop shot on match point and making the backhand pass.
"It's awesome to beat him, a great feeling," said Murray afterwards.
"He's beaten me five times in a row, so that was tough, and to do it in a semi meant it was really difficult.
"With the rain delay yesterday, and it was windy today, there were a lot of different things but I'm happy I came through in the end.
"It was really tough to serve from the near end, it was very windy, so I knew I was going to have chances to break and I just had to hang in."
Nadal stated: "I'm disappointed but at the same time I'm happy. I did a good semi-final and when I arrived I had too many matches on my shoulders. I leave the US Open with positive memories."He added: "I go on court all day with calm, try to fight as much as I can, going home knowing I tried everything.
"I had my chance in the fourth set. I just didn't come back."