Tough final

Rafael Nadal of Spain hits a return to Richard Gasquet of France during their men's semifinal match at the US Open tennis championships in New York, Sept 7, 2013.[Photo/Agencies]

Djokovic and Nadal are the most familiar of rivals and will be playing against each other for a tour record 37th time. Nadal leads their series 21-15.

"Novak is an amazing competitor," said the reigning French Open champion. "His results say he is probably one of the best players I have ever seen. He's a great champion and will be a tough final for me, but I hope to be ready for that."

While Nadal took apart Gasquet in his semifinal, Djokovic got off to a slow start against an inspired Wawrinka and relied on his stamina to wear down the Swiss.

The tumultuous match included a warning for courtside coaching from Djokovic's box, the mangling of a racket by a frustrated Wawrinka and a medical timeout for the Swiss for a strained thigh muscle.

It reached a crescendo at 1-1 in the fifth set on Wawrinka's serve.

The combatants locked into a marathon duel that lasted 21 minutes and featured a series of fierce rallies and brilliant shot-making.

Wawrinka fought off five break points among 12 deuces before closing out the game on the 30th point with a service winner, and players earned warm ovations for their desire and skill.

"These matches are what we live for, what we practise for," Djokovic said after reaching his fourth successive US Open final.

"All the credit to (Wawrinka) for being so aggressive and playing so well. I'm just fortunate to play my best tennis when I needed to."