Rio Olympics 2016: Kiwi tennis pair exit with Novak Djokovic, Andy Murray

Marcus Daniell and Michael Venus in action at the Rio Olympics. Photo / Getty Images

New Zealand's tennis Olympians Michael Venus and Marcus Daniell have gone so close to an upset in the first round of doubles in Rio before bowing out to the seventh seeds Daniel Nestor and Vasek Pospisil of Canada 6-4 3-6 6-7 (6) in two hours and three minutes.

Nestor has a current ATP doubles ranking of nine and has 90 career titles including eight Grand Slam titles while Pospisil is 17 in the world and has six titles including the 2014 Wimbledon title.

Venus is ranked 41st with four titles and two finalists finishes this year and Daniell ranked 58th has one title to his name this year.

The Kiwis started the match well taking the first set but the Canadians fought back taking the second set 6-3. It came down to the tie break and basically the final two points being the only difference between the teams.

Both combinations were successful with two breaks of serve each. The Kiwis converting two of their four opportunities while the Canadians were successful with two out of seven break point opportunities.

Meanwhile, Juan Martin del Potro is back.

Top-ranked Novak Djokovic was swept out of the Olympic men's singles tennis tournament in the first round by the 2009 U.S. Open champion 7-6 (4), 7-6 (2).

Because of three left wrist surgeries, del Potro is ranked just 145th in the world.

But when the Argentine is healthy and smacking his signature forehand around the court, his play is worthy of the gold medal match.

It was a raucous atmosphere in the last match of the night on center court, where del Potro fans chanted for him and Brazilians would try to drown out their rivals with cheers for Djokovic.

With the loss, Djokovic is still left seeking his first Olympic gold medal.

Andy Murray and his older brother Jamie exited in the first round of doubles at the Rio de Janeiro Games, making them 1-3 as a team at the Olympics.

The second-seeded British pair lost to Brazilians Thomaz Bellucci and Andre Sa 7-6 (6), 7-6 (14) in front of a loud partisan crowd Sunday night, hours after Andy won his opening singles match as the defending champion in that event.

The Murrays had their chances to extend the 2-hour match, holding five set points in the second tiebreaker, but failed to convert any.

The unseeded Brazilian duo needed seven match points to close the deal.The Murray brothers also lost in the first round of the 2012 London Olympics, and in the second round four years earlier in Beijing.

Andy is a three-time Grand Slam champion in singles, including a second Wimbledon title a month ago.

Serena and Venus Williams lost an Olympic doubles match for the first time, stunned in the opening round of the Rio Games by the Czech Republic's Lucie Safarova and Barbora Strycova 6-3, 6-4.

The Williams sisters entered Sunday's match with a 15-0 career record in the Olympics, winning the gold medal in women's doubles every time they entered the event: in 2000, 2008 and 2012.

The American duo was seeded No. 1 in Rio and coming off a 14th Grand Slam championship together, at Wimbledon a month ago.