World number one Novak Djokovic withstood a determined challenge on Saturday to reach his fifth US Open final, outlasting Swiss ninth seed Stanislas Wawrinka 2-6, 7-6 (7/4), 3-6, 6-3, 6-4.
The 26-year-old Serbian, a six-time major winner and 2011 US Open champion, will play for the title on Monday against the winner of a later match between 12-time Grand Slam champion Rafael Nadal of Spain and France's Richard Gasquet.
Djokovic booked his 12th Grand Slam trophy match, and fourth US Open final in a row, after four hours and nine minutes on his ninth ace, the sellout crowd at wind-swept Arthur Ashe Stadium giving both men a standing ovation.
"It was obvious Stan played more aggressive. He played better tennis," said Djokovic. "I was trying to hang in there, to adjust. It was tough on both of us. I had to run a lot. I had to find my rhythm.
"I was just so fortunate to play my best tennis when I needed to."
An epic third game of the fifth set lasted 21 minutes, Wawrinka fighting off five break points to hold for a 2-1 lead after 30 points, reaching deuce 12 times.
The Swiss denied Djokovic break points with forehand, backhand and service winners as well as two netted backhands by the Serb before closing out the game on a service winner.
"I was thinking, 'Whoever wins this game is going to win this match,'" said Djokovic. "After he won that game I was thinking, 'I have to fight against those odds.'"
But Djokovic finally capitalized on his eighth break point of the last set when Wawrinka swatted a backhand beyond the baseline to give him a 3-2 lead.
The reigning Australian Open champion had converted only 3-of-18 break points up to that moment, but took the critical break and held the rest of the way to advance, dropping Wawrinka to 0-13 against world number ones.
"These matches are what we live for," Djokovic said. "I want to congratulate my opponent for fighting hard until the end. It was a great match."
Wawrinka, in his first Grand Slam semi-final, fired plenty of winners early but struggled to connect on even half his first serves while Djokovic, undone by unforced errors most of the first two sets, found his form and battled back.
"It was a great tournament for me," Wawrinka said after his first Grand Slam semi-final, a run that included his quarter-final ouster of defending champion Andy Murray.
"Tough match to have lost. I gave everything. I fight until the end. I tried. It was an amazing experience."
The victory ensured Djokovic will stay atop the rankings after the US Open no matter how he fares in the final. Nadal leads their personal rivalry 21-15 while Djokovic owns an 8-1 career edge over Gasquet.
Djokovic improved to 13-2 with his 11th victory in a row over Wawrinka, who also pushed him to 12-10 in the fifth set in a fourth-round matchup at the Australian Open.
Djokovic won three of the last four points in the key second-set tie-breaker to level the match, but he was broken at love in the eighth game of the third set, netting a forehand to hand Wawrinka the momentum and a 5-3 lead.
Wawrinka won a 35-shot rally on the penultimate point of the ninth game when Djokovic netted a backhand volley and hit a service winner to seize the set.
But the Swiss double faulted away a break to give Djokovic a 2-0 lead in the fourth set and two points later slammed down his racquet, smashed it onto the court and broke it over his knee as he retrieved a new one from his bag, taking a penalty point for unleashing his frustrations upon his equipment.
After Djokovic held to 4-1, Wawrinka took a medical timeout off the court to have a right upper thigh strain treated, then ran back out and was slower with his play as both men held serve into the final set.
Wawrinka, 28, broke twice early in the first set for a 4-1 lead. Djokovic broke back in the next game only to double fault away a break at love and Wawrinka held to claim the set in only 34 minutes as his parents, Wolfram and Isabelle, looked on.
Precision shotmaking from the Swiss kept Djokovic on the defensive and paid off with a break for a 3-2 lead. Djokovic broke back in the seventh game on the way to the crucial tie-breaker.