The frontman of US punk band Green Day made a surprise appearance during a cover performance of one of the band’s songs in an Islington pub.

To the shock of many in the audience, Billie Joe Armstrong took to the stage at Slim Jim’s Liquor Store in Upper Street on Saturday (May 13).

Video posted online showed Billie Joe taking the mic during Borderline Toxic’s performance of Basket Case.

The band’s lead singer, Kerry Glass, told BBC Newsbeat: “Eleven-year-old me panicked.

"I think I did three circles just running around the stage until he was like, 'Come on, sing with me'.

"It took a minute to settle. And then I was like, 'You know, I'm going to enjoy every single second of this'."

Kerry eventually joined Billie Joe at the mic and belted out the song from the band's breakout album Dookie.

She said: “I used to sit in my bedroom and listen to all their albums. So I've got zero chill over this. This is amazing.”

After Billie Joe’s appearance, Borderline Toxic continued with their performance, following up Basket Case with one of their own songs.

Kerry said: "Then we had to follow up with an original song after that - it was wicked.

"I was like: 'Thanks for warming it up Billie Joe'."