By Larry Fine
NEW YORK, Sept 7 (Reuters) - Top seed Novak Djokovic booked the first berth in the men's final of the U.S. Open by overtaking gutsy ninth seed Stanislas Wawrinka of Switzerland in a heart-pounding five sets in Saturday's semi-finals.
Djokovic survived a courageous challenge by Wawrinka with a 2-6 7-6(4) 3-6 6-3 6-4 victory that earned both players long ovations from the Arthur Ashe Stadium crowd.
The Serb said he would grab some popcorn and recover on the couch from his four-hour tussle while watching the second semi-final between world number two Rafa Nadal and French eighth seed Richard Gasquet.
"These matches is what we live for, what we practice for," Djokovic said after reaching his fourth successive U.S. 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."
The tumultuous match, which 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, reached a crescendo in the fifth set.
With Wawrinka serving at 1-1, the combatants locked into a marathon duel that lasted 21 minutes, featuring some brilliant rallies and great shot-making in which the Swiss fought off five break points during 12 deuces and won on the 30th point with a service winner.
The marathon game earned the players several ovations in stirring tributes to their desire and skill.
But that Herculean effort seemed to sap the last bit of energy from the Swiss, who had left the court for treatment of a thigh strain during the changeover at 1-4.
Djokovic said he had to regroup after that epic game.
"Twenty-one minutes. Wow," said the Serb. "I was thinking whoever wins this game is going to win the match. I told myself I was going to have to fight again."
Djokovic held serve, then broke Wawrinka in the next game for a 3-2 lead and served out the match.
The battle was reminiscent of another classic, five-set struggle between the two in the round of 16 at this year's Australian Open, won 12-10 in the fifth set by Djokovic.
This difficult defeat came in the Swiss player's first appearance in a grand slam semi-final.
"It was a great tournament for me," Wawrinka said. "Tough match, tough loss. I gave everything. I fought until the end. With this crowd, it was an amazing experience."
Sunday, world number one Serena Williams will take on number two Victoria Azarenka for the women's singles title in a rematch of last year's championship tilt in Flushing Meadows.
The women's final will follow a men's doubles final between the second-seeded team of Alexander Peya of Austria and Brazilian Bruno Soares and fourth seeds Radek Stepanek of the Czech Republic and India's Leander Paes.
The junior boys and girls finals will also be staged on Sunday with boys' fourth seed Borna Coric of Croatia going against Australian Thanasi Kokkinakis, and second-seeded Ana Konjuh of Croatia facing American wild card Tornado Alicia Black in the girls' title match.
(Editing by Gene Cherry)