Novak Djokovic stunned by Jiri Vesely in Monte Carlo opener

The Serbian world number one, who received a bye in the first round, has been in imperious form for the past year and picked up the Australian Open title in January.

But his transition to clay did not go well as he fell to just his second defeat of 2016 - with an eye complaint partially responsible for his other loss against Feliciano Lopez in Dubai.

Djokovic had responded magnificently to dropping the first set, reeling off four games on the bounce from 2-2 in the second set, to suggest the match would reach an inevitable conclusion.

But then the unfamiliar occurred as Vesely broke twice in the decider, dominating his opponent's second serve, before serving the match out to 15. It brought Djokovic's 22-match winning run to an end, one that has helped the Serb clinch nine of his past 10 tournaments.

"It's the dream of every single player to beat a world number one," Vesely said. "For me, it's definitely a dream come true.

"When I went on court, I was hoping to win a game or to do well. But I really had no idea that I really would be able to beat Novak today. I still can't believe it happened."

Wednesday's defeat was Djokovic's earliest on the tour since he lost in the second round of the Madrid Open in 2013 and is a significant blip in his preparations for May's French Open, the only grand slam to have eluded the 11-times major winner.

"It's been a tough four or five months, so I need time to recharge," Djokovic told reporters.

It leaves the draw wide open, with Andy Murray, Roger Federer, Stan Wawrinka and Rafa Nadal all safely through to the last 16.