With Coldplay and The Killers nominated in a total of five categories at this year’s Brits, it seemed inconceivable that, between them, the two bands wouldn’t emerge from Earls Court with one or two trophies. And with that in mind, what better way to celebrate than to join forces in aid of War Child and triumphantly bash out a few tunes? In the end, both bands emerged empty-handed. If you had to guess which of the two groups might be most affronted by the perceived ignominy, chances are you would plump for The Killers’ ambitious Flowers over Coldplay’s congenitally self-deprecating Chris Martin. Oh, we of little faith. As it turned out, it was the slender black-clad Flowers who raced out onto a stage far smaller than his Las Vegas quartet have had to play in recent memory, buzzing with a life-force that could light the streets of a small market town.

The reason for his good cheer was literally staring him in the face. In the centre of the balcony Pet Shop Boys’ Neil Tennant gazed on proudly as The Killers delivered riotously joyful versions of hits such as Somebody Told Me and Mr Brightside. An hour previously, at the Brits, Flowers had presented his teenage idols The Pet Shop Boys with their outstanding achievement award and duetted with them on It’s A Sin. As a marker of ambitions realised, this must have been as real – not to mention more enjoyable – than any award. And it showed. Towering over a drum kit that barely contained the energy he unleashed on it, drummer Ronnie Vanucci was a picture of merry catharsis as, just for once, a perpetually grinning Flowers swapped imperiousness for puppyish wide-eyed glee. He paid fulsome tribute to Coldplay by declaring that, years ago, “the first time we heard this band… we felt we were in with a chance [too].”

When Coldplay finally materialized in the early hours of the morning, any similar attempts to take positives out of their Brits snub were conspicuous by their absence. “We just came back from Japan, we lost at the Brits, it’s been a shit day,” said Martin. And yet, as he bounded about the stage like a wired, punch-drunk Tigger repeatedly attempting to get back up after another rain of blows, you wondered if there was a link between the ramshackle brilliance of Coldplay’s set and the body language of a band, dressed in their customary battle gear, with a newly-sharpened point to prove. They could have hardly done so in more empathetic surroundings. “Shall we play this one? It’s a little commercial,” said Martin as he donned acoustic guitar for Yellow. He turned the microphone to face the audience, but even he seemed startled by the word-perfect clarity with which his words were sung back to him – so much so that he barely attempted to chip in.

If Neil Tennant had planned to unwind in relative anonymity after his big moment, any remaining chances of that happening were cast aside after Martin, like Flowers before him, spotted him on the balcony. With a mixture of blithe playfulness and genuine excitement, Martin pointed at him in the middle of an spittle-flecked delivery of Viva La Vida and exclaimed, “Ladies and gentlemen! The Pet Shop Boys!” Far from recoil, Tennant’s reaction was extraordinary and inspired. With the “woah-oahs” of the song resounding around the venue, Tennant raised his arms and imperiously started conducting the thousand-odd people staring back up at him.

That this impromptu spectacle was about to be eclipsed by something proper and planned was confirmed as a crowd of people, some with walkie-talkies, busily fussed at the side of the stage – and Martin declared, “Okay, you’re gonna like this a lot.” As Jonny Buckland strummed the opening chords of Take That’s Back For Good – a song which Martin has been wont to interpolate at recent performances of Coldplay’s own The Scientist – Gary Barlow gingerly walked on stage and radiated precisely the unalloyed humility that has made Take That’s resurgence such a pleasure to behold. Far from emanating the starry entitlement of a Brandon Flowers, Barlow seemed reticent to turn around and soak up the fact that, for four minutes, Coldplay were his backing band – complete with Martin living out a teenage dream and chipping in with “I want you back” backing vocals.

In terms of what followed however, this spectacle was but a mere hors d’euvres. One by one, The Killers returned to the stage and donned musical instruments. Not so much starting as slowly coalescing around a thrilling upswell of drums and feedback, the American quartet’s 2004 hit All These Things That I’ve Done took glorious shape. As noise turned into rousing clarion call, “You know you gotta help me out,” it was at this point that a black-clad Bono chose to make his entrance, beckoning the crowd to him as Martin and Flowers stood alongside him. What ensued seconds later was, in its way, possibly the most moving part of the evening. Realising that Barlow was nowhere to be seen, Martin – determined that the Take That frontman should also be in on this – almost pushed the U2 singer over in his sudden compulsion to run off in search of him.

Seconds later, all four singers stood in a perfect boy-band line just long enough for disbelieving onlookers to memorise what may go down as the most brilliantly surreal finale seen at this or any rock venue in several years. “I’ve got soul but I’m not a soldier”, they all bellowed. This wasn’t the post-Brits lap of honour that Coldplay had hoped. It was much, much better than that – and a salient reminder of what, for bands like Coldplay and The Killers, the real prizes are. With friends like this who needs awards?

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