Monte Carlo - Novak Djokovic lost only his second match of the season as he fell to Czech Jiri Vesely 6-4, 2-6, 6-4 to exit the Monte Carlo Masters on Wednesday.
"This is a proof that nobody's unbeatable. It happens so many times in my career that I lose a match. It's not a first time," Djokovic said. "It's not easy to lose the match and accept it right after exiting the court.
"But I have to congratulate my opponent. I think he played very solid.
"He was serving very big. He was playing tactically good and aggressive.
"There are a very few things I could take out from today's match as a positive -- I was playing really, really bad."
The second round loss in just over two hours, Djokovic's opening match of the tournament, nonetheless left the Serbian with an impressive 28-2 win-loss record in 2016. He was also beaten when he had to quit a Dubai quarter-final two months ago with an eye infection.
The reigning champion had not lost in 22 Masters 1000 matches since going down in the 2015 Cincinnati final and had won his last 14 matches on the ATP circuit heading into this week.
He last went out in an opening match two years ago in Madrid when he was beaten in the second round by Grigor Dimitrov.
"It's disappointing to lose the first match playing at home in a way," Djokovic said. "I practise here in these courts.
"I've lived here for the last eight, nine years. It's definitely not something that I wished and not something that I wanted. But in sport you've got to accept it.
"Time off will serve me well -- mentally mostly. It's been a tough four or five months. I need time to kind of recharge."
Vesely was stunned by his first success in nine attempts against a top 10 player.
"I fought for every point," said the Czech.
Djokovic saved a match point in the final game but it was not enough as Vesely earned two more and converted on the first of those when the seed fired wide.