Novak Djokovic crashed to his first defeat of the season with a stunning 6-4 6-4 loss to Alex de Minaur who gave Australia a 1-0 lead over Serbia in their United Cup quarter-final on Wednesday.
Djokovic was hampered by a right wrist problem in Serbia's victory over Czech Republic on Tuesday and the world number one had it worked on again by a trainer before De Minaur earned a late break and went on to clinch the opening set.
Australian Open champion Djokovic dropped serve yet again to hand De Minaur a 4-3 advantage in the second set and saved three match points later, but was unable to prevent the shock loss.