Roger Federer couldn't convert on two match points while serving in the fifth set and, for the second year in a row, the five-time US Open champion was beaten by Novak Djokovic in the semifinals of the US Open on Saturday. The top seed Djokovic, who is 63-2 on the year, won the epic clash with Federer, 6-7 (7), 4-6, 6-3, 6-2, 7-5 in three hours, 51 minutes. Djokovic will play the winner of the second men's semifinal between defending champion Rafael Nadal and fourth-seeded Andy Murray in a later match. The fifth set was even until Federer got a service break in the eighth game. Djokovic sent a forehand long to give Federer a 5-3 lead, and it was in the next game that Federer had two match points. Djokovic ended up breaking Federer's serve and then winning the final three games. There wasn't even a break point in the first set and the crowd was on its feet as the tiebreaker began. Federer took an immediate advantage by winning the first two points and four of the first six. But Federer needed five set points before he won the 55-minute first set. Federer got the break in the second set in the third game when he whipped a forehand up the line. Djokovic did get one break point on Federer's serve but he couldn't convert and soon Federer was up two sets to none. In the third set, Djokovic began moving his feet better and hitting deeper. He held serve at love and, with the help of a Federer double fault, finally broke Federer for the first time for a 2-0 lead. Djokovic immediately broke Federer to start the fourth set and broke the Swiss again in the fifth game for the a 6-2 set victory. Federer was 182-1 when wins the first two sets before the match. The last loss came at Wimbledon in the quarterfinals to Jo-Wilfried Tsonga, whom was eliminated here by Federer in straight sets in the quarterfinals. "I have had big matches where I ended up losing some, but the majority I was able to win throughout my career," said Federer. "Some of them you just have to move forward with also losses like this and not get too down about it." "The season is not over yet. I'm looking forward to what's still to come. Let's see what happens. There's still some stuff left, hometown tournament in Basel, the World Tour Finals coming up. "You can't play every season identical. You don't want it to be, otherwise it becomes boring, too," said the 30-year-old Swiss. "I guess I will be extremely hungry going to Australia next year. It's clear and obvious, and I know if I keep on working hard now that I'm feeling so good right now it will all pay off. I know it. "I haven't felt like this in a long time, so this is a good time," he said. This is the fifth consecutive year the two men have gone head-to-head in the event. Meeting in the final here in 2007 and in the semis every year since. Federer, the all-time leader in Grand Slam tournament singles titles with 16, is the only man in the Open Era (1968) to win five consecutive US Open crowns. Djokovic has put together one of the greatest years in tennis history, compiling a staggering 62-2 record before the match while winning nine titles, including the Australia Open and Wimbledon. Djokovic has won three of their four matchups this year. Federer's lone triumph came in the semis at Roland Garros.