The night before the tournament starts, a “parade of nations” – 200 players from the men’s and women’s teams representing the 16 nations taking part – makes its way down Fremont Street. While the Oscars are taking place 400km away, in Los Angeles, some of the game’s giants – both literally and figuratively – take to their own red carpet, surrounded by 10,000 fans and the street’s unique, surreal sights and sounds: models clothed only in strategically placed shiny stars, nuns, superheroes, nurses and cowboys all offer titillating photo opportunities – for a tip. The cast of characters thronging Fremont Street would not look out of place, in fact, in the Hong Kong Stadium’s South Stand.

Players high-five rugby fans and tourists alike, while Team USA star winger Perry Baker poses for selfies under the flashing lights of the Golden Nugget casino.

Baker photo safely Instagrammed, nightlife options for rugby fans intent on a liquid diet abound. The Light nightclub, at the Mandalay Bay Resort and Casino, offers fans holding a Sevens ticket both free entry and an open bar until midnight. While trying to force my way to the bar, I realise there’s a reason the words “open bar”, “free” and “rugby fans” rarely appear together in the same sentence.

The tournament itself – this being the 15th annual edition – is held at the Sam Boyd Stadium, home to University of Nevada Las Vegas Rebels Football, just outside the city limits. The location lacks the walkable convenience of Hong Kong Stadium – although a weekend shuttle pass for US$35 includes unlimited rides, each of which takes 40 minutes, for the three days from a number of hotel lobbies – but what it does have is a backdrop of golden desert, red mountains and clear, crisp blue skies. Nevada has little rainfall, so the 40,000-seat stadium features open stands on all sides. In early March, Vegas temperatures hover around 15 degrees Celsius; the cool, sunny conditions feel ideal for watching rugby.

Scalpers wander the vast car park, but official US$216 three-day general admission tickets are still available. Next to the stadium sits the International Fan Festival, a “global celebration of rugby on and off the field”. It is beautifully delivered through a mix of stands serving food from the nations taking part in the tournament – Aunty Devi’s New Zealand meat pies, chai tea with samosas from Kenya, real-deal chicken curry from Fiji and excellent charcoal-grilled teriyaki – and craft beer, live music and entertainment stages, merchandise tents and screens showing the action. This being Vegas, also on offer are helicopter rides, for a bird’s-eye view of the action.

Flags of the participating countries (there’s no team from Hong Kong) are draped around shoulders as fans inside the stadium juggle enormous plastic cocktail glasses, foam gloves and hot dogs. Mingling with the ranks of green and gold following the Wallabies and dancing Kenyans are countless Fijians from across the United States and further afield, joining what is their community’s biggest annual get-together.

Donald Trump rubber masks worn under “Make America Great Again” caps are cheered and booed in equal measure while groups of men dressed as cheerleaders, a galaxy of astronauts and a family of crocodiles meet only with approval. The big screen focuses in on other costumes: a stripy team of Where’s Waldo (or Wally); a court-full of John McEnroes, circa 1981.

A critical part of the Hong Kong Sevens atmosphere is the music, and Vegas delivers that, too. Bobby McFerrin’s Don’t Worry Be Happy, U2’s Beautiful Day and Wham’s Wake Me Up Before You Go Go get things started, before House of Pain’s Jump Around, Chumbawamba’s I Get Knocked Down (But I Get Up Again) and Cypress Hill’s Insane in the Brain take the crowd up a level – or three.

On the third day, in the final for fifth place, the Wallabies kick off against the All Blacks to the sound of arguably the most famous Sevens anthem, Sweet Caroline, as wandering beer sellers keep spectators lubricated. Churros, pretzels and nachos are offered to soak up the intake. In common with Hong Kong, the vibe is friendly, with perhaps more eyes on the field than on the stands.

“Rugby is so fast-paced, but the thing I really like about it is the community around it,” says Mike Keller, who has flown in from Minneapolis and is a comparatively recent convert. “They play really hard during the match, but once it’s done, everyone is still friends.”

He asks me whether the French also get booed in Hong Kong – as happened in their victory against Kenya a couple of hours earlier. Naturally, I decline to comment.

With their home advantage, Team USA sweep all before them. After beating England in the quarter-finals, they over­come tournament favourites Fiji 19-7 in a match that includes perhaps one of the greatest individual tries at a Sevens. The 31-year-old Baker takes the ball from his own try line, weaving through the opposition at breathtaking speed before coolly placing it between the posts.

“There are way too many distractions in Vegas!” says a Fijian fan who has flown in from New Jersey, trying to explain why his team underperformed. “You could tell they didn’t have much energy.”

Before he can explain further, My Heart Will Go On comes over the sound system, an invitation for him and many others to adopt the Kate Winslet pose from Titanic.

The final pits the US against Argentina. The Himno Nacional Argentino must rank as one of the world’s longest national anthems; just when you think it has finished, another verse launches, much to the amusement of the partisan home crowd. Baker is again the star, scoring the first try in a 28-0 rout that leaves even the most ardent American fan stunned at the nature of the whitewash.

As the cries of “USA! USA!” ring out around the Sam Boyd Stadium, no one could begrudge the fans their moment – nor indeed the city of Las Vegas its achievement as host to a sporting weekend with few parallels.

Chris Dwyer was a guest of MGM Resorts in Las Vegas. This year’s USA Sevens takes place on the weekend of March 1