Juan Martin del Potro is proving to be Novak Djokovic’s Olympic curse…

For the second Olympics in a row, the 27-year-old Argentine player has taken down Djokovic.

del Potro, who beat the current ATP World No. 1 in the bronze-medal play-off at 2012 London Games, again overpowered Djokovic, taking down the Serb tennis star in the first round at the 2016 Rio Games 7-6 (7-4) 7-6 (7-2).

Djokovic was in tears as he left the court after the match, which lasted two and a half hours.

“This is one of the toughest losses in my career,” said Djokovic, who was trying to win his first Olympic title.

Djokovic became the first man for 47 years to hold all four Grand Slam titles by winning the French Open in June.

He suffered a shock third-round loss to American Sam Querrey at Wimbledon but won his 30th Masters title in Toronto last week.

“It’s not easy to handle, especially now, just after the wounds are still fresh,” he added after failing to improve on the bronze he won at the 2008 Beijing Games.

“But you have to deal with it. It’s not the first or the last time that I have lost a tennis match. But the Olympic Games, yeah, it’s completely different.”

del Potro will face Portugal’s Joao Sousa in the second round on Monday.

The former US Open winner has dropped to 141st in the world after two years of injury problems but did not face a single break point on his serve against the 12-time Grand Slam champion.

“It was a wonderful evening from the beginning,” said del Potro.

“After all the effort I’ve put in to get back to playing tennis, I’ve defeated the number one. It was a dream night.”