Novak Djokovic's final preparation for the French Open ended when he lost in the Geneva Open semi-finals to Czech world number 44 Tomas Machac.

World number one Djokovic, who turned 37 this week, was beaten 6-4 0-6 6-1.

The Serb has not reached a final in 2024 before starting the defence of his French Open crown.

The clay-court Grand Slam tournament starts at Roland Garros on Sunday.

Djokovic, who has won a men's record 24 major titles, entered Geneva to build up court time after a difficult start to the season by his standards.

After losing in the Australian Open semi-finals to Italy's Jannik Sinner, Djokovic was knocked out of Indian Wells at the last-32 stage.

He did reach the semi-finals in Monte Carlo at the start of the clay-court swing, but at his next outing at the Italian Open, Djokovic was accidentally hit on the head by a metallic water bottle after his opening win.

Two days later, he lost to 32nd-ranked Alejandro Tabilo of Chile.

Djokovic won his opening match in Geneva against Germany's Yannick Hanfmann, who beat Andy Murray in his opener, and defeated Dutchman Tallon Griekspoor.

But he again looked out-of-sorts against Machac and also showed signs of physical discomfort in a one-sided deciding set.

Djokovic will start his bid for a fourth French Open title on either Monday or Tuesday against a French wildcard Pierre Hugues-Herbert.