Bradley Cooper delighted fans at Lady Gaga’s Las Vegas show when he joined her on stage for a surprise performance.
The duo performed Shallow from their film A Star Is Born during Gaga’s Enigma residency show on Saturday night.
In video clips shared on social media from concert-goers, Gaga sits at the piano while Cooper is on a stool as they sing the Oscar-nominated track together.
As the song reaches its climax, he joins her on the piano bench and puts his arm around her, to cheers from the crowd.
US film critic Kevin McCarthy was among those sharing clips on Twitter, and he said it was “insane” to see the pair perform together.
In another tweet, he wrote: “What an amazing show. Cooper was sitting right behind us. We said hi a couple times. I was wearing a Jackson Maine shirt. Wow. Amazing seeing them do that live.”
Cooper and Gaga are both nominated in the main acting categories at the Academy Awards, along with Shallow, which is up for best original song.
The film is also shortlisted for best picture, although Cooper – who made his directorial debut with the remake of the classic film – did not score an Oscar nod in the directing category.
Cooper is, however, nominated for best director at the Baftas.
A Star Is Born tells the tragic love story of Maine, played by Cooper, who helps Gaga’s struggling artist Ally.