NEW YORK -- A little more than an hour after wasting two match points and losing in the U.S. Open semifinals, Roger Federer headed for the exit.
Dressed in his on-court outfit -- powder-blue shirt, brown shorts, custom-made sneakers with the New York skyline sketched on the heels -- Federer walked out of Arthur Ashe Stadium, accompanied by his wife. Between licks of a lollipop, he paused to tell tournament workers, "See you next year."
So used to playing in the final at Flushing Meadows, the five-time champion left earlier than usual. With everyone expecting a Rafa vs. Roger title match at the U.S. Open, Novak Djokovic got in the way.
Djokovic prevented what would have been the eighth Grand Slam championship match between tennis' top two men -- and first such showdown at Flushing Meadows -- by coming back to stun Federer 5-7, 6-1, 5-7, 6-2, 7-5 in Saturday's semifinals.
"They all pretty much feel the same. They feel somewhat empty at the end, because you have tried everything -- and maybe it was luck. Maybe it was he played well. Maybe you didn't pick the right shot. Maybe he did," said Federer, who had won 45 of his previous 46 matches at the U.S. Open, reaching six consecutive finals.
"You feel like you left something out there if you lose a match having had match point," Federer added. "It wasn't a final, so I'm not as disappointed if it would have been a final."
His loss means that the third-seeded Djokovic will be standing between No. 1 Rafael Nadal and a career Grand Slam in the final Sunday, when the forecast calls for a 50 percent chance of rain. Nadal owns eight major titles but never had been past the semifinals at the U.S. Open before beating No. 12 Mikhail Youzhny 6-2, 6-3, 6-4 earlier Saturday.
Nadal will be bidding to become the first man since Rod Laver in 1969 to win the French Open, Wimbledon and the U.S. Open in the same season. The 24-year-old Spaniard also can become the seventh man in tennis history to own at least one championship from each Grand Slam tournament.
"I won't watch," Federer said, "but I hope he wins."
Federer's record 16 Grand Slam titles include the 2004-08 U.S. Opens, but he repeatedly let leads slip away against Djokovic. Federer took the first set, then the third. Even after Djokovic forced a fifth set, Federer twice was a single point from winning.
"One of those matches," 2008 Australian Open champion Djokovic said, "you'll always remember."
With the crowd in Arthur Ashe Stadium trying to will Federer to victory -- because of the tantalizing prospect of a final between him and Nadal -- he couldn't close the deal. Nadal and Federer have played in seven Grand Slam finals: three at Wimbledon, three at the French Open and one at the Australian Open.
They've never met in any round at the U.S. Open, mainly because Nadal couldn't hold up his end of the bargain. He lost in the semifinals in 2008 and 2009, and earlier in previous years.
For Federer, Saturday's setback comes after losses in the quarterfinals of the French Open and Wimbledon, and he closes the 2010 Grand Slam season having played in one major final -- the first year since 2003 that he hasn't reached at least two.
"It's only going to fuel me with more motivation to practice hard and get back to Grand Slam finals, which I haven't been in for the last three Slams," Federer said. "I feel like I'm playing well, and I would have deserved to be in the finals tomorrow."
Saturday's action concluded under the lights, with No. 2-seeded Kim Clijsters easily beating No. 7 Vera Zvonareva 6-2, 6-1 in 59 minutes for her third U.S. Open title. Clijsters is the first woman to win the tournament in consecutive years since Venus Williams in 2000-01.
Federer's 3-hour, 44-minute loss to Djokovic was by far the day's best match, much more entertaining than the men's semifinal that preceded it.
Nadal dominated with his serve again, holding 13 of 14 times Saturday, making him 89 of 91 for the tournament.
"After a lot of work," said Nadal, who hasn't dropped a set these two weeks, "I am here in the final."
In 2008, he lost in the semifinals to Andy Murray, and now says he was wiped out mentally after a long, if successful, summer that included a gold medal at the Beijing Olympics. In 2009, he lost to eventual champion Juan Martin del Potro, while dealing with achy knees and a torn abdominal muscle.
"Well, it's another step, I think, in my career, so for sure it's a very important victory for me," Nadal said. "To be in the final of the last Grand Slam of the year is something new, because I always arrived here with problems."
Not this year. He took three weeks off after Wimbledon -- skipping Spain's Davis Cup quarterfinal -- to rest and get treatment on the knees that bothered him so much of last season and the beginning of this season.
"Tough to say who is better than Rafa," Youzhny said. "I mean, he's No. 1 and he played really good tennis."
Plus, Djokovic needed to put in a lot more work than Nadal on Saturday and, unlike at the other Grand Slam tournaments, won't benefit from a day off between the semifinals and final.
"I am tired. There's no secret about that," Djokovic said. "For four sets, I've been quite OK. Fifth set was very intensive, mentally and physically, and it took a lot out of me."
Told it's supposed to rain Sunday, Djokovic opened his eyes wide and rubbed his hands together.
"I don't know the rituals, how to invite the rain," he said. "An extra day would be great."
He is always rather demonstrative, and Saturday was no different. After losing one point, he whacked himself in the head a few times with his racket. After another, he pounded his leg with the racket. And after several others, he would put his hands on his hips and shake his head.
But Djokovic never gave up, even after getting broken at love in the next-to-last game of the first set, then losing serve in the last game of the third. Instead, he kept flustering Federer, who hadn't lost a 6-1 set at the U.S. Open since a 2001 defeat against Andre Agassi.
Djokovic showed off tremendous defensive skills, sliding on the hard court the way he would with red clay underfoot, his sneakers squeaking loudly with each step, and forcing Federer to hit extra shots. Federer wound up with 66 unforced errors, 28 more than Djokovic.
The Serbian saved the match points while trailing 5-4 in the fifth set and serving. He erased the first with a swinging forehand volley winner to cap an 11-stroke point, and the second with a forehand winner, then wound up holding for 5-all. The only service break of the fifth set would come in the following game, when Federer missed forehands on the last two points to allow Djokovic to go ahead 6-5.
Djokovic then served out the victory -- although only after saving one last break point. Federer let that slip by pushing a forehand long, then set up Djokovic's first match point with a forehand into the net.
The last point went 22 strokes, culminating with Federer sending a backhand wide.
Djokovic held his arms up, and looked up at his guest box, where his parents -- wearing T-shirts emblazoned with likenesses of their son -- were jumping and hugging. Djokovic stared ahead, his jaw agape, as though even he couldn't quite believe what he accomplished.
"It's really hard to describe the feeling I have right now," Djokovic said in an on-court interview. "I was a point from losing this match, and now I managed to come back."
Djokovic had lost to Federer at each of the previous three U.S. Opens, in the 2007 final and the 2008-09 semifinals. That was part of why everyone was expecting to see the 22nd career meeting between Federer and Nadal. They would have been the first pair of men to meet in the finals of all four Grand Slam tournaments.
Instead, Sunday's final will have, coincidentally, the 22nd career meeting between Djokovic and Nadal, one of whom will become a U.S. Open champion for the first time.
"To be honest, I was just closing my eyes and hitting forehands as fast as I can on match point. If it goes in, it goes in. If it goes out, just another loss to Federer in the U.S. Open," Djokovic said. "I managed to come back. I was very lucky."