Justin Timberlake strutted his stuff in front of a star-studded audience - including his wife Jessica Biel, Justin Bieber and Gemma Arterton - for a post-BRIT Awards gig at the HMV Forum in Kentish Town last night (20.02.13).
Bieber, 18, arrived discreetly midway through the show, flanked by security guards, and perched himself on the celebrity-packed upper tier balcony, where he appeared to be enthralled by Timberlake and sang along to his 2006 song Until the End of Time.
Clad in his trademark baseball cap, sunglasses, hoodie and a white T-shirt, Bieber didn't look at or talk to any of his fellow concert-goers and was solely concentrated on the stage.
The Canadian singer, in London for the latest dates on his Believe world tour, didn't stay for long as he made a swift exit after just 10 to 20 minutes, before Timberlake, 32, performed his new single, Mirrors, which he also sang earlier in the night at the BRITs.
Bieber tried to make an incognito exit but turned heads as he tripped over one of his bodyguards and nearly fell.
Total Recall actress Biel clearly enjoyed seeing her husband on stage, as she was on her feet all night singing along and dancing, and was seen happily smiling and waving at excited fans.
An onlooker said: "She knew the lyrics to all of his songs. It was so sweet. She was looking at him very lovingly."
As well as dancing, the 30-year-old screen was seen chatting to former Bond girl, Arterton, 27.
Other stars who attended the concert included all four members of JLS - J.B. Gill, Marvin Humes, Aston Merrygold and Oritse Williams - as well as Sir Tom Jones and Kelly Brook.
As well as performing songs from his new album The 20/20 Experience, Timberlake thrilled fans with his greatest hits, including Cry Me a River, What Goes Around and Like I Love You.