Rome:Novak Djokovic rallied after a rain delay to beat Roger Federer 4-6, 6-3, 6-3 on Saturday and reach the Rome Masters final, extending Federer's title drought to seven months.
It's the second consecutive Masters Series final on clay for Djokovic, after the Serb lost to Rafael Nadal in Monte Carlo two weeks ago.
Federer wasted breaks in both the second and third sets.
"I feel like this is not a match I should have given away," Federer said. "I usually don't give away opportunities like this."
Djokovic will face Nadal again in Sunday's final, after the top-ranked Spaniard cruised past 12th-seeded Fernando Gonzalez 6-3, 6-3.
Nadal extended his clay-court winning streak to 29 matches _ stretching back to an opening-round loss to Juan Carlos Ferrero here last year.
Nadal also beat Gonzalez in the 2007 final, and his career record in Rome is 21-1 with three consecutive titles from 2005-2007.
Nadal holds a 12-4 career edge over Djokovic. Although in Monte Carlo, Djokovic became the only player to take a set on clay from the Mallorca resident this year.
"I learned that I have to really play every point against him," Djokovic said. "So that's what I'm going to try to do tomorrow."
Federer has not won a tournament since taking the title at home in Basel, Switzerland, in October. He opened the clay-court season with a third-round loss to fellow Swiss player Stanislas Wawrinka in Monte Carlo.
Rome is a key warmup for the French Open, which begins in three weeks and is the only Grand Slam title missing from Federer's collection of 13 majors.
"It's bad, but I still have some work to do on the clay," Federer said, referring to the upcoming Masters tournament in Madrid. "I have the feeling that maybe since I had the back problem, my serve is just not working there where I want it to be. That's something I have to make sure I can fix for Paris."
Djokovic needs to defend his title at the Foro Italico to prevent Andy Murray from taking the No. 3 ranking from him.
Djokovic began working with former Roland Garros winner Thomas Muster's old trainer Gebhard Phil-Gritsch last week, and he grew sharper than Federer as the match wore on.
The match was suspended for about an hour due to rain with Federer up a set and 2-1 in the second. When the sun re-emerged, Federer had a chance to go up two breaks before Djokovic won five straight games to rally from 1-3 down and force a third set.
"I was patient more, and playing more compatible and wiser after the break," Djokovic said. "More on his backhand side, and trying to wait for chances. I think that was the key."
Federer's backhand gave him trouble in the decider.
A backhand drop-shot attempt from Federer landed in the net to hand Djokovic a break and a 4-3 lead, and the Swiss player then missed a routine backhand into the net on Djokovic's second match point.
Overall, Federer committed 42 unforced errors to Djokovic's 39.
Federer took control of the opening set when Djokovic was bothered by a whistle from the crowd.
Djokovic had already tossed the ball into the air for his second serve on break point when the whistle interrupted him. He let the ball drop to the ground without hitting hit and glared up into the stands. He managed to get the serve in on his next try but then missed a forehand long to hand Federer the break.
Fans started chanting "Out, Out" to encourage security officials to remove the whistler from the stadium, but it was unclear if they did.
Federer dropped to 7-4 in his career against Djokovic, who also won their last meeting at the Masters Series event in Key Biscayne, Florida, a month ago.