RIO DE JANEIRO: Juan Martin del Potro, of Argentina, returns to Novak Djokovic, of Serbia, in the men’s tennis competition at the 2016 Summer Olympics in Rio de Janeiro, Brazil, Sunday. — AP RIO DE JANEIRO: Juan Martin del Potro, of Argentina, returns to Novak Djokovic, of Serbia, in the men’s tennis competition at the 2016 Summer Olympics in Rio de Janeiro, Brazil, Sunday. — AP

RIO DE JANEIRO: Juan Martin del Potro stunned a tearful Novak Djokovic in an emotional Olympics triumph on Sunday as Venus Williams pondered the end of her four-gold Games odyssey. Del Potro, the 2009 US Open champion who was pushed to the brink of retirement by a series of wrist injuries, downed the top seed 7-6 (7/4), 7-6 (7/2).

The giant Argentine had also defeated the 12-time major winner in the bronze medal match at the London Olympics in 2012. Both players embraced at the net and wept at the end of their centre court duel played out in front of a raucous Argentine and Serb crowd. Del Potro, now ranked at 145 in the world after being number four in 2010, said Sunday's win was more special than his victory in 2012. He had his first surgery in 2010 but more followed in 2014 and 2015 when he played just six events.

"This victory is bigger than last time because I know how tough it was to come back from three surgeries," said the 27-year-old who unleashed more than 40 winners.

"Tonight I played one of the best matches of my career." Del Potro started the day by getting stuck in an elevator for 40 minutes at the athletes village where he had to be rescued by the Argentina handball team. But that inconvenience did not shake the Argentine out of his big-hitting stride as he set up a second-round clash with Portugal's Joao Sousa.

'DELPO BETTER PLAYER'

"Delpo was the better player and he deserved to win. That's sport," said world number one Djokovic, whose Olympic singles record is stalled at a bronze from Beijing in 2008. "It's very sad and disappointing to go out of the tournament this early but I am glad that a good friend of mine, who has struggled with injuries, has won." Meanwhile, four-time gold medallist Venus Williams was staring at the end of her 16-year, five-Olympics journey.

Williams, 36, and sister Serena suffered their first ever defeat in women's doubles, a record which boasted 15 successive match wins and golds in Sydney in 2000, Beijing in 2008 and London four years ago. The 6-3, 6-4 loss to Czech pair Lucie Safarova and Barbora Strycova came just a day after Venus had been knocked out of the singles in what was her first opening round Olympics loss.

Venus, a seven-time Grand Slam title winner and the 2000 Olympic champion, said she and Serena will now focus on the US Open later this month. "It was not our best day," said Venus who will be 40 when the next Olympics rolls around in 2020 in Tokyo.

Serena, 34, was more damning.

"We played terrible and that basically showed," she said. At least, Serena is still alive in the singles as the defending champion had the perfect start in her quest for a fifth Games gold medal overall, defeating Australia's Daria Gavrilova 6-4, 6-2. Williams, sporting a patriotic Stars and Stripes hairband on centre court, will next face Alize Cornet, the Frenchwoman who defeated her three times in 2014, including at Wimbledon.

London 2012 winner Andy Murray and 2008 Olympic champion Rafael Nadal breezed through in the men's singles. Wimbledon champion Murray, the second seed, clinched an eighth win in eight meetings against Serbia's Viktor Troicki, 6-3, 6-2. Murray, playing for the first time since securing his second career All England Club title, next faces Argentina's Juan Monaco, one of his closest friends on tour.

There was one blot on the day for Murray as he and brother Jamie were knocked out of the men's doubles by Brazil's Andre Sa and Thomaz Bellucci. Nadal, playing his first match in two months, made the second round with a comfortable 6-2, 6-1 win over Federico Delbonis of Argentina. The 30-year-old Spaniard, sidelined by a left wrist injury since the French Open, set up a clash with Italian veteran Andreas Seppi who he has beaten eight times in nine meetings. German second seed and Australian Open champion Angelique Kerber hit back from 2-5 down in the second set to defeat Mariana Duque-Marino of Colombia 6-3, 7-5.

French Open champion Garbine Muguruza romped to a 6-2, 6-2 win over Romania's Andreea Mutu who was a late replacement for Jelena Jankovic who withdrew with a shoulder injury. - AFP