And when he dropped his serve to trail 6-5 in the opening set, he then reacted by taking a ball out of his pocket and hitting it towards the back of the court.
Unfortunately, in his rage, he struck a lines judge.
Djokovic went to check on her wellbeing but, after discussions with tournament officials, he was then disqualified from the competition.
That robbed him of the chance to win another Grand Slam, with Dominic Thiem going on to lift the trophy instead.
And Djokovic, speaking afterwards on Instagram, revealed the whole situation left him ‘sad and empty’.