Metallica paid tribute to Green Day over the weekend, as the Bay Area metal band filled in for the Bay Area pop-punks at the Voodoo Music + Arts Experience in New Orleans.

“The world needs them,” Metallica frontman James Hetfield said on stage about Green Day, who’d canceled their performance after singer-guitarist Billie Joe Armstrong headed to rehab. Then Metallica busted out the opening riff of Green Day’s 2004 American Idiot title track. “That’s all we had time to learn,” Hetfield quipped as the band cut the song off early to rummage through Metallica’s more than ample back catalogue. Watch the video above, via Blabbermouth, which has posted professional footage of Metallica’s full set.

Metallica guitarist Kirk Hammett elaborated further in an interview earlier this month with Fuse. “We got a message [in early October] asking us if we’re able to fill in for Green Day, because Billie Joe was having some issues,” Hammett is quoted as saying. “We discussed it between the four of us and we all said, ‘Yeah.’ It would be great thing for us to do and it would also be great to help out Billie Joe, ’cause he’s a friend of ours and we love Green Day. If we can help them out in any way possible, we’re always happy to do it, ’cause we love those guys. It’s actually an honor for us that they approached us and asked if we can fill in.”

Metallica are set to put out the first release on their own label, a Montreal live DVD, on December 10.