World number one Novak Djokovic was dumped out of Rio Games in the first round on Sunday by Argentina's Juan Martin del Potro, who also defeated him in the bronze medal match at the London Olympics.

Del Potro, former U.S Open champion ranked 145 in the world after an injury-hit few years, stunned the Serb with a powerful display to win 7-6 (4), 7-6 (2) in the biggest upset in the tennis tournament.

It was yet another huge shock after the Williams sisters and Murray brothers lost in their first-round matches in the doubles on a dramatic day.

Djokovic was very emotional as he departed the scene.

Earlier in the day, Del Potro was caught up in an incident which went viral as he was trapped in a lift at the Olympic village and had to be rescued by the Argentina handball team.