Black Sabbath guitarist Tony Iommi has revealed he was “extremely nervous” before the band’s first concert since his recent lymphoma battle, explaining he wasn’t sure he’d have the endurance to make it through an entire set.

In a post on the band’s newly-updated website, Iommi admits to not “knowing whether I’d be able to last” through a full-length concert. Luckily, as he explains it, the energy of his bandmates carried him through the show: “It turned out to be no problem whatsoever because Ozzy (Osbourne), Geezer (Butler) and (tour drummer) Tommy (Cluefetos) were nailing everything, no chance to feel tired!”

By all accounts, the concert — a fundraising show at the O2 arena in their hometown of Birmingham — was a smashing success, with Osbourne leaping about the stage like a man half his age as Iommi led the band through 19 of their classic songs. Iommi wraps up his account by thanking the crowd and declaring, “I’m really pleased with how it turned out.” On June 10 the band will headline the Download Festival in Derby, England, and on Aug. 3 they will make their only stateside appearance at Chicago’s Lollapalooza festival.

Watch Black Sabbath Perform ‘Into the Void’ in Birmingham