It’s not often a star like Pitbull is relegated to a support slot, but Mr. International knows his audience well here. In a surprisingly wholesome moment from a set that mostly revolves around twerking dancers, Pitbull tell us crowd that when he was asked to tour with tonight’s headliner, he jumped at the chance - because he relates to her, he says. They’re both people who’ve, triumphed over adversity, beaten people who wanted to see them fail - and come back stronger.

The rabid 3arena crowd lap this up, of course - it’s this overarching career narrative that means Britney fans will never turn down a chance to show their appreciation for a star that once looked like it was in danger of burning out.

When Britney’s Piece of Me Las Vegas residency was announced in 2013, it seemed like the star was going into semi-retirement. While the hits hadn’t dried up since her infamous 2007 breakdown, her personal life was still in some turmoil, her money and affairs legally controlled by her father by court order.

Instead the show revitalised the reputation of the strip’s entertainment offerings, drawing the likes of J-Lo and Lady Gaga to accept similar residencies. Four years later and $150 million earned, she’s finally back on the road, taking the Piece of Me tour around the world - to rumours that her father is prepared to hand her back control after this tour.

The night’s opener reveals the secret to this success - 'Work Bitch' and its hot-body/Maserati mantra is an anthem for the ages that playfully demonstrates the attitude that’s spawned so many hits over 20 years.

Of course she mimes throughout the night, but nobody who knows Britney expected anything else. She’s left to focus on working with her dances through lung-busting routines. Britney moves in a fashion not unlike a wind-up doll, precise and efficient but not exactly the most fluid.

The furthest reaches of her back catalogue are delved into only occasionally, and 'Oops I Did It Again' and 'Baby One More Time' are mashed together in a slowed-down arrangement accompanied by spooky fog and visuals of flocks of ravens. The past is clearly a murky place for Britney.

We’re taken on brief excursions to different themes explored throughout her career. A highlight is a visit to the club realm, heralded by the giant figure of will.i.am onscreen, 'Scream and Shout' over the PA, and her dancers emerging in lurid neon gear.

There’s also a trip to the art-deco world of the roaring 20s for a simmering 'I’m a Slave 4 U', where Britney cavorts on a pole and brings up an audience volunteer, throws a harness on him, whips him and makes him crawl across the stage. It’s a piece of stagecraft marred slightly by the faux-British accent she adopts while explaining what’s about to happen.

It’s perhaps fear of these faux pas, or the clear and obvious distinction between her high-pitched speaking voice and breathy recorded vocals that keeps these bits of audience interaction to a minimum - we can count them on one hand tonight. It leaves a slightly hollow feel to the show -  for all its pyrotechnics, confetti cannons and expert choreography, there’s little in the way of personal connection.

Still, you can’t argue with the hits though, and 'Toxic' is followed by a triumphant 'Stronger' - “my loneliness ain’t killing me no more”.  Here’s hoping she won't stay in Nevada so long again.