One of the biggest surprises of San Diego Comic-Con weekend had nothing to do with movies or comics. Instead, it came in the form of an unforgettable rock collaboration as Iron Maiden frontman Bruce Dickinson made an unannounced appearance during The Coverups’ performance, joining Green Day’s Billie Joe Armstrong for a rousing rendition of Mott the Hoople’s classic “All The Young Dudes.” The surprise performance took place during Fandom and Z2’s annual San Diego Comic-Con Party at FLOAT inside the Hard Rock Hotel San Diego, where Armstrong’s covers band, The Coverups, headlined the unofficial kick-off celebration for Comic-Con. The unexpected appearance immediately sent the packed crowd into a frenzy as Dickinson walked onstage to perform one of rock’s most iconic anthems alongside Armstrong and company.

Watch Bruce Dickinson & Billie Joe Armstrong On Stage

The collaboration felt especially fitting given Dickinson’s long history with the song. The Iron Maiden vocalist previously recorded his own version of “All The Young Dudes” for his 1990 solo album, Tattooed Millionaire, making the Comic-Con performance both a nostalgic callback and a rare opportunity to hear him revisit the David Bowie-penned classic in a live setting.

The annual Fandom x Z2 Comic-Con Party has become one of the most anticipated events surrounding San Diego Comic-Con, bringing together actors, musicians, creators, industry professionals and fans for an evening celebrating pop culture, gaming, comics and entertainment. This year’s edition, presented by Xbox’s Halo: Campaign Evolved, once again delivered one of the convention’s biggest talking points thanks to Dickinson’s surprise guest appearance.

For Iron Maiden fans, seeing Bruce Dickinson perform “All The Young Dudes” live is an exceptionally rare treat, especially alongside one of punk rock’s most recognisable frontmen. The collaboration bridged generations of rock music and proved that even during Comic-Con weekend, some of the biggest moments happen when the lights go down and the amplifiers get turned up.