Novak Djokovic's bid for a fourth Madrid Masters title is over after he was beaten 6-3 6-4 in the second round by Italian Matteo Arnaldi.
It was a first career win against a top-five player for Arnaldi, 24, who was facing the Serbian fourth seed for the first time.
"He's my idol, he's always been, so I was just glad that I could play him," Arnaldi said.
"To play him on a stage like this was already a victory for me.
"But he's not at his best right now so I came on court to try to play my best tennis and win and it happened, so right now I don't even know what to say.