Rafael Nadal, right, and Marc Lopez, of Spain, celebrate after defeating Canada in their men's doubles match. Photo: Charles Krupa

Rio de Janeiro - World No 5 Rafael Nadal, the Beijing 2008 gold medallist, is guaranteed another Olympic medal after reaching the men's doubles final with Marc Lopez on Thursday.

The Spanish pair defeated Canada's Daniel Nestor and Vasek Pospisil 7-6(1) 7-6(4) in a tight semifinal lasting a minute over two hours, played on a packed Court 3 at the Olympic Tennis Centre.

Having secured victory, Nadal and best friend Lopez celebrated wildly, Lopez falling to the ground in tears and the 14-time Grand Slam champion kissing him as he lay flat on his back on the court.

By reaching the doubles final at Rio 2016, Nadal now has the chance to become the fourth player in the modern era of tennis in the Olympics (since Seoul 1988) to own gold medals from both the singles and doubles events.

Venus Williams, Serena Willams and Nicolas Massu are the players to have already achieved this, with Massu doing so in one Games, at Athens 2004.

“I'm very happy, extremely excited and [to] enjoy this moment here in the Olympics, especially with one of my best friends, with Marc, is something unforgettable,” said Nadal, who was uncertain if he would even compete in Rio because of the wrist injury that had kept him out of competition since Roland Garros.

“We are extremely happy, with high emotions on court, lots of nerves, we really enjoy it a lot. Just a moment to enjoy because we have a silver and now try and be ready for tomorrow.”

When Nadal and Lopez go for gold in the doubles final on Friday, they will also bid to secure Spain's best-ever result in Olympic men's doubles, as they seek to improve on the silver medal won by Sergio Casal and Emilio Sanchez 28 years ago in Seoul.

Their opponents in the doubles final will be Florin Mergea and Horia Tecau, who stand to make a bit of history of their own.

The Romanian duo, who beat Americans Steve Johnson and Jack Sock 63 75 in their semifinal, have already guaranteed their country's first Olympic tennis medal of any colour.

What's more, Romania has yet to win a medal in any sport at the Rio 2016 Games. As losing semifinalists, Johnson and Sock will now meet Nestor and Pospisil in the bronze medal match on Friday.

For 43-year-old Nestor, this will be a pitch at a second Olympic doubles medal, having taken home gold from Sydney 2000 with Sebastien Lareau, but all the other men on court will be gunning for their first podium finish. In women's doubles, the semifinalist pairs are now known following Thursday's quarter-final matches.

The Czech Republic will definitely win a medal in this event, by virtue of having two teams through to the last four: Lucie Safarova and Barbora Srycova, first-round conquerors of the Williams sisters, and Andrea Hlavackova and Lucie Hradecka, London 2012 silver medallists.

Unseeded Safarova and Strycova defeated five-time doubles Grand Slam champions Sara Errani and Roberta Vinci 46 64 64 in their quarter-final, and will play two-time major winners Ekaterina Makarova and Elena Vesnina in the semis, the Russians advancing against Garbine Muguruza and Carla Suarez Navarro 63 64.

Hlavackova and Hradecka overcame Daria Kasatkina and Svetlana Kuznetsova 61 46 75, and face Timea Bacsinszky and Martina Hingis next. The Swiss pair defeated Hao-Ching Chan and Yung-Jan Chan 63 60.

The women's doubles semifinals will take place on Friday, with the bronze medal match on Saturday and the gold medal match on Sunday. The mixed doubles event got underway on Thursday after being delayed by a day due to Wednesday's washout.