Rome - Germany's Alexander Zverev stunned four-time Rome champion Novak Djokovic 6-4, 6-3 to win his first Masters title on Sunday, confirming his status as a French Open dangerman.
The 20-year-old Zverev claimed his maiden Masters 1000 title after becoming the youngest player in a decade to reach a final at this level and will move to 10 in the world as a result of his impressive victory.
Despite a clinical straight sets win over Austrian Dominic Thiem on Saturday, world number two Djokovic produced a flawed performance on centre court that saw him curse and swear as he struggled to find a way back into the match.
Overall, Djokovic had 27 unforced errors to 14 for Zverev, who also had 16 winners to the Serb's 11.
Zverev now has four career titles, three of which have come this year, while Djokovic, who turns 30 on Monday, was denied what would have been a record 31st Masters title.
"Playing against Novak, one of the best players to ever play - it was an honour being on the court with you," said Zverev, the first player born in the 1990s to win a Masters title.
"You're an amazing player. Unfortunately this week you didn't win, but I'm sure as we get closer to Paris you'll be one of the favourites for the title."
Zverev broke in the first game of the final on his way to the first set and carved out the crucial first break of the second set in the third game.
"I knew I had to be aggressive from the first point on and to the last," added Zverev, who has known Djokovic for many years having trained with the Serbian.
"It was very important for me to be able to stay this aggressive and don't let him take over the game.
"Against someone like Novak, it's always very tough to get into rallies. I thought maybe if he's a bit cold, he'll give me one or two unforced errors in the beginning which can help me to break him.
"So all tournament I served quite well, so I was quite comfortable on my serve. It was more a question if I could break him. I wanted to get a shot from the beginning, so it worked out well."
Despite playing twice on Saturday, when he was forced to complete his rain-interrupted quarter-final against Juan Martin del Potro before facing Thiem, Djokovic struggled to find rhythm against Zverev.
He complained of conditions that were "completely different", with "a lot of wind and just very fast and bouncing (balls)".
He was quick to applaud his conqueror, calling Zverev's win "absolutely deserved".
But he added: "On the other hand, I mean, he didn't get much from my side. I played very poor today. Just couldn't find any rhythm."
Djokovic's frustrations boiled over when he was handed a warning for an audible obscenity in the eighth game of the second set before he was broken again in the ninth as Zverev celebrated his first Masters title.
Despite the defeat, Djokovic will start the French Open, which gets underway next Sunday, as one of the leading favourites having completed the career Grand Slam in Paris in 2016.
He then confirmed eight-time Grand Slam title winner Andre Agassi would coach him in Paris.
In the WTA event, Ukraine's Elina Svitolina continued her brilliant season with a clinical 4-6, 7-5, 6-1 upset win over injury-hit Simona Halep.
Halep, who won the Madrid Open last week, needed treatment after going over on her right ankle in the second set as she hit a return from the baseline.
In the decider, the Romanian, who had won 26 of her past 30 matches on clay, was visibly hurting and was helpless to prevent Svitolina from claiming her fourth title of the season after wins in Taipei, Dubai and Istanbul.
Svitolina now has a tour-leading 31 match wins this year.
"I think I can be proud of myself for handling the pressure, because I played some tough matches here. Today I needed to show that I am there and I want to win and I'm ready to do it," said Svitolina.
Halep added: "I never like to give up during the match. I don't want to stop the matches. So I just wanted to try to win the second set."