AFP - New Zealand collapsed after a perfect start to hand Samoa a 24-21 win and the showpiece Hong Kong Sevens on Sunday in a repeat of the Las Vegas final.

And after three days, 60 games, 846 minutes of rugby, and more than half a million pints of beer in the humid southern Chinese sunshine, thousands of jubilant supporters watched Samoa crowned champions.

The Kiwis, holders of nine previous Hong Kong titles, were unable to avenge their defeat to Samoa in the US in February, leaving the Pacific islanders to take the glory in a thrilling finale in front of a 40,000 capacity crowd.

"It was like any other cup final. At 14-0 down we had to keep our composure and they stuck to their guns right until the end," Samoan coach Stephen Betham said.

"I think the people back home will be so happy. The boys just played their hearts out for the people back home."

Hong Kong is the sixth stop on the eight-leg Sevens World Series with further tournaments to come in England and Scotland.

There was action on and off the pitch for the thronged spectators to enjoy, including a punch-up as the French took defeat to the Portuguese rather badly and bars selling an estimated half a million pints of beer.

"This is my first time and it's amazing. I've seriously never seen so many fit men in one place," said travel agent Sarah Kukri, 28, from London, who was enjoying punch and canapes in the hospitality village.

She could have been talking about the players but was actually referring to the thousands of spectators who turned up clad in a wide variety of fancy dress, including as superheroes, Native Americans, boxers, strongmen, cavemen, spacemen and postmen.

New Zealand drew first blood in the final with quick scores under the posts for Kurt Baker, the four-try star of the Kiwis' semi-final win, and were 14-0 up before Samoa had even touched the ball.

But the pre-tournament form team drew level at 14-14 by half-time with Simaika Mikaele forcing his way through from close range out wide to open Samoa's account.

Scoring machine Mikaele Pesamino, who was later named player of the tournament, broke through to touch down under the posts for the Samoans to hand them the initiative immediately after the break.

New Zealand could have levelled the tie again through DJ Forbes but Australian referee Andrew Lees missed what looked like an obvious off-the-ball foul on the veteran forward as he hared after his own up-and-under.

Pesamino seized the initiative for Samoa, breaking one tackle to score under the posts after taking the ball at speed in the midfield, putting the Pacific islanders 24-14 ahead.

New Zealand weren't finished and replied under the posts with the last move of the game, but it was too little too late.

"We ran out of time but we shouldn't have let it get down to that," Forbes said after the hooter.

"We were trying to score off everything when we needed to settle down and set up a few more rucks.

"We've been behind in the World Series before and we've come through. Hopefully we can turn things around but obviously the key will be the team that works the hardest over the break and hopefully we'll get up for the next two."

Organisers hope the Hong Kong Sevens, where thousands of fans -- many of them in fancy dress -- roared on 24 teams over three days of rugby, will have reinforced interest in the sport ahead of its Olympic debut in Brazil in 2016.

Hong Kong took the fourth-tier shield final to rapturous applause and a standing ovation, beating Russia 19-17.

Canada took the third-tier bowl while Australia won the consolation plate competition.

Samoa, who last won in Hong Kong in 2007, had held off England in the semi-finals 28-24.

New Zealand were also pushed to the limit against defending champions Fiji in a festival of running rugby which proved to be the most entertaining game of the competition.