Peter Burling and Blair Tuke gold medal favourites

Blair Tuke (right) and Peter Burling PHOTO/SUPPLIED

Tauranga sailor Peter Burling and team-mate Blair Tuke have made an brilliant start to their Olympic regatta, taking two race wins on the opening day of racing in the men's 49er.

Burling and Tuke, the four-time world champions, underlined their status as gold medal favourites, playing the light winds perfectly on the in-shore course at Guanabara Bay.

"We're really happy to get a couple of low scores on the board and not walk away with anything big and just to get into the series, you know, we've been waiting a long time to get racing, and we've been really enjoying ourselves out there and I think that showed today," Burling said.

The Kiwi pair got a little bit lucky in the opening race, capitalising on a late error from the Danish crew of Jonas Warrer and Christian Peter Lubeck, who had led for most of the race.

The Danes inexplicably missed the final top mark, sailing well beyond the mark before realising their error and turning back. It cost Warrer and Lubeck seven places, with the Danish pair eventually finishing eighth.

Burling and Tuke once again played the conditions perfectly in the second race, establishing themselves among the early leaders before making their move on the final upwind leg to take the lead at the last mark rounding.

The strong opening day sees Burling and Tuke hold a handy six-point lead at the top of the standings, with Portugal second on eight points, and the German crew in third.

The defending Olympic champions and Burling and Tuke's main rivals for gold, Australian pair Nathan Outteridge and Iain Jensen, are in 11th place after recording finishes of 13th and eighth in the two races.

The fleets faced long delays before racing got underway today as officials waiting for the wind to build. The delay meant only two of the three scheduled races were sailed in the 49er class.

The light conditions did not play into the hands of the women's 470 pairing of Jo Aleh and Polly Powrie.

The Kiwi duo, collectively known as Team Jolly, have lost their overnight lead, slipping back to sixth in the standings after a 12th place finish in the only race of the day. British crew Saskia Clark and Hannah Mills - Team Jolly's key rivals for gold - have powered into the lead at the half-way point in the regatta.

Aleh and Powrie's disqualification in the opening race of the regatta is coming back to haunt them. Had their original sixth place finish stood, they would be joint leaders with the Brits now with virtually identical results.

They are not out of gold medal contention yet however, with the women's 470 fleet one of the most tightly contested, with just six points separating the top six.