Novak Djokovic suffered a setback before the French Open by losing to Tomas Machac in Geneva.

Machac captured the biggest win of his career as a 6-4 0-6 6-1 victory saw him reach his first final at the Geneva Open.

The world number one appeared out of sorts and received a medical timeout at the end of the first set, which he had led 4-1 before fading.

Switzerland Tennis Geneva Open
Novak Djokovic (right) congratulates Tomas Machac after losing in the semi-final of the Geneva Open (Martial Trezzini/Keystone via AP)

Djokovic broke for a 3-1 lead and seemed in command, but his Czech opponent – who had pushed him hard in Dubai last year before losing – stepped on the gas to win five successive games.

The second set was a different story as Djokovic produced several superb forehand winners to level the match in style.

Djokovic won the opening game of the deciding set, but it was downhill after that as another surge from Machac proved unstoppable.

The Serb now heads to Paris where he faces France’s Pierre-Hugues Herbert in the first round.