Karen Khachanov upset a tired-looking Novak Djokovic 7-5, 6-4 to win the Paris Masters title and deprive Djokovic of the chance on Sunday to match Rafael Nadal's record of 33 Masters titles.
Djokovic, a record four-time champion at the indoor event, looked out of energy after an epic three-hour semifinal win against Roger Federer on Saturday.
After also being taken to three sets by Marin Cilic in Friday's quarterfinals, Djokovic's semifinal finished at around 8 p.m. local time and he felt he was unable to recover sufficiently from that draining encounter.
"I didn't unfortunately. But I don't want to talk about that," Djokovic said. "I want to talk about how well (Khachanov) played all week and absolutely deserved to win today."
Asked again whether it was a case of emotional fatigue, after such an intense tussle with Federer, Djokovic repeated his praise for Khachanov.
"Karen played really well and he deserved to win," Djokovic said. "All the credit to him."
Although Djokovic broke in the fourth game to move 3-1 up and then led 30-0 on serve, the unseeded Khachanov broke him straight back and the momentum abruptly shifted away from Djokovic.
"I stepped in more inside the court," Khachanov said. "I started to move him and maybe he didn't expect that I could do it after being down 3-1 with a break."
Djokovic seemed agitated at times and twice turned to his box to remonstrate about an unspecified issue during the first set.
Khachanov broke for 6-5 when he hit a powerful shot down the line that Djokovic could only scoop back into the net. The Russian won the first set with a big first serve that Djokovic could not return, stretching out his racket in vain as the fizzing ball clipped the frame.
Djokovic struggled to handle Khachanov's brutal two-handed, cross-court backhands from the baseline, which often landed near his ankles, and dropped his serve again to trail 2-1 in the second set. He had to save three more break points in the seventh game to hold for 4-3 down.
"He was playing big from the back of the court, flat backhands and forehand. He can really hurt you," Djokovic said. "His serve is really, really strong and precise."
After both players held to love, Khachanov showed no nerves — even though he was in his first Masters final — and served out the match.
He secured victory on his first match point when Djokovic chopped a backhand return wide. The imposing Khachanov thrust both his arms in the air and, moments later, knelt down to kiss the court.
"It's a breakthrough season. And this title, it's a good year-end I would say," Khachanov said. "Maybe I'm not crying, but still I'm really happy."
Djokovic will return to No. 1 in the rankings for the first time in two years on Monday, but the Serb will be disappointed at missing out on a 73rd career title, having withstood the best of Federer on Saturday.
Still, the Wimbledon and U.S. Open champion has plenty to feel good about after a 22-match winning streak, and he remains favourite for the season-ending ATP Finals in London, beginning Nov. 11.
"I'm satisfied of course and I'm going to be No. 1 tomorrow. What more can I ask for? I mean, I won 20-plus matches in a row and had a most amazing last five months," he said. "I'm getting into (the) season finale feeling good about my game."
The 22-year-old Khachanov, ranked 18th, is the first Russian to win here since Nikolay Davydenko in 2006. Marat Safin won it three times before that.
Two-time Grand Slam champion Safin won the last of his Paris Masters titles in 2004 when Khachanov was a young boy.
"I watched (Safin's) matches but later, not at the age of eight," he said. "I'm just really proud of myself that I could be in this list of winners."
Khachanov added this title to the Kremlin Cup in Moscow last month for his third title of the year and fourth overall.
He had won his previous three finals and said his 100 per cent record helped him when he stepped on the court against the 14-time Grand Slam champion.
"I was thinking, 'OK, (Djokovic) has, I don't know, 70 titles and I have three,'" Khachanov said. "But 3-0, you know? So maybe it was in the back of my mind."