Harry Styles, Zayn Malik, Louis Tomlinson, Liam Payne and Niall Horan stepped out of their car to rapturous screams from thousands of fans as they hit the red carpet for the world premiere of their highly-anticipated film, This Is Us.
Dressed in coordinating black, the boys spent time chatting to ecstatic fans, happily posing for photographs and signing autographs as they slowly made their way inside the cinema.
Thousands of their supporters had travelled from around the world to be a part of the event, which Niall, 21, described as "the best night of our careers".
Despite their huge international fame, the boys still seemed overwhelmed by the display of devotion from the 'Directioners' — which quickly drew comparison to the scenes of Beatlemania, when 12,000 fans took over Piccadilly Circus for the 1964 premiere of A Hard Day's Night.
"This is unreal," said Harry, 19, while Liam, 19, added, "I honestly can't believe we are here."
Harry brought along his proud mum and step-dad to the screening, while Louis attended with his girlfriend Eleanor.
Zayn's Little Mix girlfriend Perrie Edwards turned up wearing a diamond ring, sparking rumours of an engagement.
Harry said that their "all-access" film is a love letter to their fans. "We just wanted to say a massive thank you to them," Niall added. "This is amazing. We're really excited to be here. We can't believe we are here."
A host of celebrities turned up to show their support for the band, including father-to-be Simon Cowell, who attended with two of his ex-girlfriends, Mezghan Hussainy and Sinitta.
The music mogul took a break from his holiday in the Mediterranean to support his former X Factor stars — and made light of the pregnancy revelation.
Speaking about his pride at how far the band had come, Simon said, "This is a dream come true, I feel like a father… But we won't go there!"
Rolling Stones star Ronnie Wood showed up and said he was "very proud" of the boys and has "been keeping an eye on them". Marvin and Rochelle Humes, beautiful in a black and floral Dolce & Gabbana dress, Diana Vickers and Amelia Lily were also on the guest list, alongside McFly and, of course, the film's director Morgan Spurlock.
He said fans would enjoy seeing how "normal" the band are. "There is no air of superiority, there is no air of success that permeates this movie.
"You see five guys who are the same five guys they were three years ago."