WATCH: Bradley Cooper, Pearl Jam share the stage at BottleRock Napa Valley

Bradley Cooper also appeared with Golden State Warriors star Steph Curry and celebrity chef Jose Andres during the festival.

Eddie Vedder had a big surprise in store for fans during his band Pearl Jam’s headlining set on Saturday (May 25) at BottleRock Napa Valley.

And it was none other than Oscar-nominated movie star Bradley Cooper.

The 49-year-old Hollywood A-lister took the stage late in the band’s set to do a duet with Vedder on “Maybe It’s Time,” a song Cooper originally recorded for the 2018 film “A Star is Born.”

The two traded verses on this Jason Isbell-penned country ballad while Vedder softly picked away at an acoustic guitar.

Thousands of smartphones simultaneously rose in the air to capture the performance, as fans documented for their social media feeds what was certainly one of the defining moments of the 2024 BotttleRock Napa Valley.

Watch Cooper and Vedder perform “Maybe It’s Time” by clicking on this video as well as this one.

At the conclusion of this song — which Vedder has covered previously as well — Cooper departed the stage and Pearl Jam continued its march toward the finish line with “Crazy Mary,” “Do the Evolution” and “Alive.”

Yet, the actor would then reportedly return to the fold for the final selection of the night, helping these Seattle rockers close up shop with a fierce version of Neil Young’s “Rockin’ in the Free World.”

It was the big finale to what had been a really huge day for Cooper, who also appeared earlier on Saturday at the festival’s Williams Sonoma Culinary Stage with Golden State Warriors star Steph Curry and chef Jose Andres.

Cooper, who grew up just outside of Philadelphia, was there to promote his cheesesteak business.