They may have been two members down, but the pop group Katseye received a hero's welcome as they played their first full concert in the UK.
The audience erupted with screams even before the show began, as the band broadcast their music videos on the O2 Arena's big screens, and the noise barely dipped for the next three hours.
It was proof that Katseye have become pop's biggest property (they're currently the most-streamed act on YouTube UK) even while singers Manon Bannerman and Sophia Laforteza are on health-related hiatus.
The stage felt emptier without them, but their bandmates worked hard to fill the gaps, hyping up the crowd with a succession of bass-heavy pop anthems and jaw-dropping dance breaks.
"Are you happy to see us?" asked the band's youngest member, Yoonchae Jeong, as if the answer hadn't been obvious from the moment they appeared in a storm of laser lights and launched into the Brazilian funk workout of Hootie Frutti.
"I think you guys are our loudest crowd ever, literally," marvelled Megan Skiendiel.
"This crowd is unbelievable," added Lara Raj.
The concert was only the second date of the band's Wildworld tour - but fans already knew every twist and turn from social media.
There was even a cheer of relief when Daniela Avanzini survived a complicated lift in the dance routine for Gabriella. On the opening night, her dance partner dropped her.
Such adulation - and scrutiny - has come quickly for Katseye.
Based in Los Angeles, the multinational girl group were only formed in 2023 as part of the online reality competition show The Debut: Dream Academy.
The contest was created by Hybe, the South Korean entertainment company behind acts like BTS and Le Sserafim, and the US record label Geffen, home to Olivia Rodrigo and the Rolling Stones. Of the 120,000 who initially applied for the show, only six made it through.
Trained under the rigorous K-Pop system, they had a breakout year in 2025, first with the hyperactive electro-skronk of their single Gnarly, then with its follow-up, a slinky ballad called Gabriela that highlighted Daniella's Cuban-Venezuelan roots.
In London, their audience skewed young: The queue for pick and mix was longer than the one for the bar.
When Megan asked, "Whose first concert is this?" the air curdled with screams.
Throughout the show, fans shook lightsticks, parroted Katseye's dance moves and, in some cases, spontaneously burst into tears.
Many concert-goers also wore bindis, inspired by Lara, who has proudly incorporated her Asian heritage into her aesthetic.
One individual also came dressed as a courgette, a reference to Internet Girl's so-weird-it-almost-works refrain, "Eat zucchini".
The energy was infectious. And, if you looked closely, the parents were enjoying the show as much as their kids.
Even Spice Girl Melanie C is a fan, hosting a Q&A with the band during their first UK trip last October.
"They're incredible girls," she told the BBC earlier this summer. "They've got great music, they've got a great work ethic, and they're really beautiful, you know?
"Obviously, they've had a little drama, as happens with all bands, but they work so goddamn hard."
The drama began in February, when Manon announced she was taking a hiatus from the band to "focus on her health and wellbeing".
It came after the Swiss-Ghanaian singer told BBC News the band had been subject to racism and death threats; but fans also highlighted Katseye's gruelling schedule, suggesting they were being overworked.
Then, just months after Manon stepped back, Sophia announced she was also going on hiatus to protect her "mental health and wellness".
"You can't pour from an empty cup," she posted on social media. "It's important to care for yourself."
Other highlights included Daniela's death-defying dance break, complete with aerial splits, that led into Gabriella; and Megan's technotronic shakedown at the end of Pinky Up.
For Yoonchae, the show's high point was Time Lapse, where she got to sing in her native Korean, while mingling with the crowd. ("Keep your hands to yourselves and don't throw any gifts on the stage for our safety," warned Lara, spoiling the atmosphere just a little).
The show ended on a powerful note, with Iconic By Mistake - the band's defiant response to an online hate campaign - and an extended romp through Gnarly, complete with a leather-studded rock remix.
All told, it was a stunningly confident and self-assured show from a band who could easily been diminished by personnel problems.
"This is not a goodbye," promised Yooncahe as Katseye waved goodbye. "We'll come back."
Glastonbury's Pyramid Stage would be a perfect fit.
