The audience was largely under 18 and almost exclusively female - no surprise there then since the stage was set for One Direction.
In fact, pretty much the only males in the building seemed to be those on stage and the phalanx of black-clad security guards stopping any of the frankly hysterical throng from getting to them.
After a rather wry video introduction depicting "1D" holding court at "the party of the year", Niall Horan, Zayn Malik, Liam Payne, Harry Styles and Louis Tomlinson stepped gingerly out from behind screens.
Perhaps they were daunted by the intense reception, or maybe they are still getting used to their astonishing global fame, which has seen them rival even the Beatles in single sales.
Fighting to be heard above the screaming, they launched into Up All Night, followed by I Would and Heart Attack.
The crowd were on their feet from the start and sang along with every word of every one of the erstwhile X Factor finalists' frothy hit songs.
"It's loud in here," remarked the outfit's resident Irishman Horan, from Mullingar in Co Westmeath, with some understatement.
Every young lady in the hall seemed to have dressed to impress her favourite member.
But there's a hint with One Direction that they might know how daft the whole enterprise is and are just having fun with it.
Certainly, a mid-section interlude that saw the quintet gamely answer audience members' tweets and sing and dance to snippets of The Fresh Prince of Bel-Air and U Can't Touch This showed they have a sense of humour.
They also played a brilliant series of video sketches featuring the vocalists in various disguises 'pranking' passers-by in London.
You've also got to respect the fact that One Direction performed last night without the need for a squad of backing dancers, an overly elaborate stage show or even the dreaded boy band staple, stools.
It was just them and a four-piece live band, bouncing about in skinny jeans, Ramones T-shirts and messy hair, with the occasional detour to a secondary stage in the centre of the arena.
Sure, the group's covers of Blondie's One Way or Another and Teenage Kicks by the Undertones remain scrappy shadows of the originals, but there was no denying the thrill of hearing an arena full of kids – many of whom weren't even born last century, never mind in the 1970s – singing along with the punk classics.
But the best party in town had to fizzle out sometime.
After nearly two hours of demented, piercing screaming and sugary, pumping pop-rock, it was becoming a challenge for this writer to process what was going on around him.
Rock Me seemed winningly catchy, as did one called She's Not Afraid, while Live While We're Young surely summed up the mood.
I think I caught Malik giving the crowd "at least a 12" out of 10, and I'm pretty sure I saw Horan brandishing a guitar.
If it was all starting to mush together into one primary-coloured, hormonally charged screech, then that's this old git's problem, and not One Direction's, who have at least five years before they have to start thinking about solo careers or reunion tours.
And the likes of Justin Bieber could learn a thing or two from the band's punctuality.
Any parents reading this review who are being dragged along to one of the remaining shows this week will be pleased to know that the five-piece came on stage bang on time at 8.30pm last night and finished promptly at 10.30pm.
The queues to get out of the car parks, though, were more No Direction than One Direction.