Novak Djokovic's conqueror Jiri Vesely has admitted that he had "no idea" he could upset the world number one at the Monte Carlo Masters.

Djokovic lost a completed match for the first time since August by going down in three sets to the Czech in the second round in Monaco.

"When I went on court I had completely different thinking, like I hope to win a game or I really hope to do well," PA quotes Vesely as saying.

"But I had no idea I would be able to beat Novak today. So for me it's just something that I can't believe really happened. I hope it will give me a lot of confidence, a lot of self-belief."

It was Djokovic's earliest loss at a tournament for three years and the Serb was quick to congratulate Vesely.

"Obviously it's not easy to lose the match in terms of accepting it, but I have to congratulate my opponent," Djokovic said. "He was playing bravely. He was going for it and he deserved to have it."

Vesely, the world number 55, will next face Gael Monfils in the last 16.