Second-seeded Nadal beat eighth-seeded Richard Gasquet 6-4, 7-6 (1), 6-2 in the second semifinal a much less dramatic affair than the opener, in which Djokovic could feel the stakes rising with every point he played at 1-1 in the fifth.
"Well, I was thinking I guess everybody was thinking 'Whoever wins this game is going to win the match,'" Djokovic said. "After he won the game, I thought to myself, 'OK, I guess I have to fight against those odds.'"
He did, to improve to 20-7 in five-set matches, and now, Nadal and Djokovic will meet Monday in their third final at Flushing Meadows in the last four years, the only break coming last year when Nadal was out with a knee injury. They split the first two meetings, with Nadal winning in 2010 and Djokovic in 2011.
"Novak is an amazing competitor," Nadal said. "His results say that he is probably one of the best players that I have ever seen."
Nadal won easily despite dropping his first service game of the tournament. He had extended his streak to 73 when Gasquet broke him in the fourth game of the second set. Both men held until a second-set tiebreaker, which Nadal won 7-1 to end what little drama existed in the afternoon's second match.
Fans certainly got their money's worth in the first one.
"I managed to find my way through, to adjust, and to win," Djokovic said. "That's what counts."
His victory will be remembered mostly for a game he lost the third game of the final set, a back-and-forth roller coaster ride in which Djokovic had five opportunities to break for a 2-1 lead and lost them all.
Ninth-seeded Wawrinka had eight game points. Before the last, he gestured to the crowd to pump up the volume. Sensing the opportunity, Djokovic hammed it up, as well. Wawrinka followed that well-deserved break in the action with a 123-mph service winner up the middle.
"It was a really long game with some good points and some big mistakes," said Wawrinka, of Switzerland, who made it farther than his country's most famous player, Roger Federer, for the first time in any of his 35 Grand Slam appearances.
• Men's doubles championships, 10:30 a.m., ESPN2
• Women's championship, 2:30 p.m., Ch. 2