He only picked up the oval ball for the first time last summer but American Carlin Isles, already dubbed the "fastest man in world rugby", is one of the players fans most want to watch at the Hong Kong Sevens.
A former US top 40 100-metre sprinter with a personal best time of 10.13 seconds, Isles contacted USA Rugby last year to ask for a game after watching sevens online.
And although he had never played before, he showed such promise that he was given a spot on this season's Sevens World Series team.
In their first match in Hong Kong Friday it was Isles who put the USA on the scoreboard against Kenya with a try from a typical lightning break down the right wing.
But the physical Kenyan side, an emerging force in sevens rugby, went on to win the close encounter 17-14.
"I work on my speed a lot and I believe in my speed, so I'm very confident," he told AFP.
"It was very physical -- those guys are very big and I'm probably the smallest out there. But I'm a tenacious person... it's just about getting the technique."
The 23-year-old from Ohio -- who is just 5ft 8in (173cm) and 160 pounds (73kg) -- said he was attracted to rugby by the physical and mental toughness required.
Sevens also offered him the chance to compete at Olympic level -- it will feature for the first time in Rio in 2016 -- after Isles missed out on US team selection for the 100 metres in London.
"I feel at home now with the rugby. It teaches you discipline," he told AFP.
While he says a shot at the Olympics was a factor in his switch, he also wanted to set an example.
"I wanted people to understand that if you put your mind to anything you can do it," he said.
A compilation video entitled "Carlin Isles. Olympic Dream" showing him outsprint opposing players to score tries in this World Series has gone viral on YouTube, with almost three million views since it was posted in December.
But Isles says he wants to be known as a good all-round player.
"I don't want to be a sprinter playing rugby, I want to be a rugby player that's a sprinter," he said.
While the Hong Kong Sevens is known for its party atmosphere, unlike the majority of his fans in the crowd this weekend Isles has never touched alcohol.
"My parents always told me to be different -- I'm not a conformist, I work hard and I'm a dedicated person. All that unnecessary stuff I didn't put on my resume," he said.
Having just lost out to France 21-19 on the second day of the tournament Saturday, the USA were bottom of their group with series leaders New Zealand still to face later in the day.
But whatever happens in Hong Kong, their minds are on 2016.
"The Olympics is always our goal," said Isles. "But for now we're just trying to get better each day."