Alessi Rose proves she is the moment at landmark Koko show.

Alessi Rose is onto something special. Monday night at Koko is yet another landmark night for the star who, frighteningly, is only at the beginning of leaving her mark on the big pop world.

A lot can happen in a year. Strolling over to Koko in Camden, the idyllic St Pancras Old Church creeps up over the road. The building casts a calming shadow in the early spring sun. It’s with a wry smile to think back to a first visit to that church fewer than 12 months ago. On that night, a doe-eyed Alessi Rose played out her first tales of heartbreak with a huge grin across her face at a debut headline show - the stained glass rattling in the windows.

That venue held just 100 people and now, just five minutes down the road, there’s a sold out crowd of 1,500 ready to worship the 22-year-old’s melodramatic pop. Part of the For Your Validation Tour, the London date sold out in rapid time and, on the day, freshly listed resale tickets are snapped up in seconds. There are few more prestigious venues in London than Koko - not only a rite of passage for artists but young music fans too. Lady Gaga, Halsey and Katy Perry are just some of the pop titans who played formative shows between those four walls. Now it’s Alessi Rose.

There’s a religious fervour to Monday night and that is no accident either.Just as Alessi was aware of the irony of debuting her winking ballads at St Pancras Old Church, there’s a huge cross that hovers over the stage as Koko and the star struts out to a motto of, ‘Forgive me father for I have sinned’. The night kicks off with undeniable swagger on the brilliantly radio-ready ‘IKYK’. What follows over the next 60 minutes is nothing like I have ever seen at Koko before - and nothing I have seen an artist without a full record to their name stir up.

By the time that opener’s bridge arrives, Alessi has dropped to her knees and is rolling her eyes at the womaniser targeted by the flick. Brimming with confidence, moments when the reality of the night sinks in seem few and far between but there is an endearing split-second of bashfulness during ‘eat me alive’. That’s soon brushed away as the star screams a welcome to the crowd.

Giddy masochism is very much bread and butter for Alessi Rose. The euphoria of her Koko set comes in a lust for the spectacle of heartbreak. ‘break me’ transcends the studio version to shake the walls of Koko and ‘CRUSH!’ is an early magnum opus that the songwriter lets rip with a bang.

The singer has already earned a reputation for having an eye for a cover and doesn’t disappoint on the For Your Validation Tour. Previous takes on Chappel Roan and Lorde showed an artist aware of who else is on her listeners’ playlists but, this time around, Alessi takes the risk of journeying all the way back to 2004 with Gwen Stefani’s ‘What You Waiting For?’. The result? Her best cover to date.

The star is at her most convincing when upping the ante but Alessi is no one-trick pony. There are heartfelt moments of intimacy at Koko, the first in ‘don’t ask questions’. From her second EP, that track was the project’s most head-turning listen on release with its bedroom confessions. It’s clearly resonated too - those lines now sung back by thousands.

Elsewhere, ‘lucy’ and the unreleased ‘stella’ draw on a ‘friendship breakup’ and show the vulnerable Derby girl behind a star on the rise. ‘imsochillandcool’ is another highlight of the set in an acoustic track that could fill any venue.

The night ends on a high after the singer dons a sash from a fan that reads, ‘Validating my sold out tour’. There’s a dreaminess in the production of ‘start all over’ that feels like some sort of trip to wonderland and ‘oh my’ is perhaps Alessi’s best songwriting to date - the genius lyric of ‘He gives me head while I’ve been losing mine’ a timeless pop moment. Having taken the magnitude of her biggest headline to date in her stride, Alessi allows the first signs of tears to show as the opening tones of closing number ‘pretty world’ sound. That single is a hopeful ode on a brighter future and, as confetti cannons fire, it’s a poignant moment to end on. Watching back videos from last night, it’s a similar feeling to the one after St Pancras Old Church last April, and then Hoxton Hall in September. Somehow, Alessi is already bigger than the very, very big things she is doing.

The singer may just be a 22-year-old with two EPs to her name, so the hyperbole still sometimes feels far-fetched, but the time to speak quietly about the star is long gone. Alessi Rose is the moment and, if you’re not shouting about her now, you soon will be.