Djokovic’s fourth straight win over Federer and his 25th in 47 contests sends him into the final against unseeded Russian Karen Khachanov, who has never played in a Masters final.
“This is my best match of the year, that’s for sure. Big respect to Roger,” Djokovic said, addressing the crowd in French. “Whenever I play Roger he demands the best of me.”
Federer remains one short of 100 career titles.
“When you lose a close match like this you always have regrets,” the Swiss said. “Losing is never fun, so that’s why I guess I have this face right now.”
Djokovic is on a 22-match winning streak and will aim to move level with Rafael Nadal on a record 33 Masters titles.
“Novak is obviously on a roll. You can feel it,” Federer said. “He protects his serve very well.”
Earlier, Khachanov continued his strong recent form by beating Dominic Thiem 6-4, 6-1. Khachanov won the Kremlin Cup in Moscow last month for his third career title.
Djokovic, who beat him on the way to the Wimbledon title, is seeking a record-extending fifth Paris Masters title and 73rd title overall.
The Paris fans got everything they could have hoped for – two players with a combined 34 Grand Slam titles, 59 Masters titles, and 533 weeks at No.1 slugging it out in unrelenting yet sublime intensity.
Brilliant one-handed winners on the run from Federer and acute-angle volleys at the net; astonishing elasticity while retrieving from the baseline and laser-beam forehands to the corners from Djokovic.
Federer had 17 aces, while Djokovic got five of his eight in his last three service games, stepping up his level at the right time.
Djokovic briefly let his volatile temper get the better of him, though, when he had Federer at 15-40 down in the ninth game of the deciding set. Federer saved both break points, and Djokovic whacked his racket into the ground, drawing the first and only boos of a titanic match.
Djokovic jogged over to get a new racket and held his hands up as if to apologise to the unforgiving crowd.
Brimming with confidence in a season which has seen him go from No. 22 in the rankings in May to No. 1 when they are releasedtomorrow, and in which he has added the Wimbledon and US Open to his Grand Slam haul, Djokovic created pressure throughout.
But Federer saved every break point – 12 of them – and secured the only break of the match in clinching the second set.