Andrey Rublev denied Novak Djokovic a first title of the season by beating the world number one in the final of his home tournament at the Serbia Open.
Faced with a partisan home crowd, world number eight Rublev dominated the deciding set to win 6-2 6-7 (4-7) 6-0.
Djokovic was visibly fatigued in the decider in what was a first final in a disrupted season for the Serb.
The win gives Russian Rublev, 24, a third title of the year and a first victory over Djokovic in his career.
Djokovic, 34, had only won two matches in 2022 going into the clay court event in Belgrade but showed his trademark grit to force a decider for the fourth match in a row.