The British rock duo were performing at the US city’s Slim’s venue on Wednesday night (April 15), with the pair inviting Ulrich to pick up the sticks for set closer ‘Out Of The Black’.
The band’s own drummer, Ben Thatcher used the moment to stagedive into the crowd. Watch fan-shot footage below.
The band first met Ulrich when he attended the group’s San Francisco show last September.
As previously reported, after the show Royal Blood were taken to the house from the Mrs Doubtfire film by Ulrich.
Following the incident, Royal Blood took to Twitter to post a photo of the occasion, which can be seen above. The caption read: “Tonight took a turn. Lars @Metallica took us to Mrs Doubtfires house.”
The gig was also attended by Muse and Rage Against The Machine’s Tom Morello – who also tweeted his support of the band after the event, stating: “I’ve seen the future of riff rock and it’s name is #RoyalBlood”.
Royal Blood released their chart-topping self-titled debut in August 2014. They took home the prize for Best British Group at this year’s Brit Awards and also won Best New Band and Best Live Band at this year’s NME Awards with Austin, Texas. The NME Awards ceremony took place at London’s O2 Academy Brixton in February.