Bradley Cooper And Lady Gaga Performed 'Shallow' Live For The First Time

Gaga surprised her fans in Vegas when her "A Star Is Born' co-star jumped on stage.

Fans absolutely lost it when they realised that Cooper was in the crowd and making his way to the mic.

The actor hugged Gaga, threw off his incognito baseball cap was hooked up with an earpiece.

"Jason never used these," Cooper joked of his stubborn A Star Is Born character, Jackson Maine.

"I can't hear anything," he added. "Hello, Vegas!"

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The duo then belted out the movie's hit tune, "Shallow", which is up for Best Song at the Academy Awards next month.

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Lady Gaga's Little Monsters have been overwhelmed with emotion after watching the pair bring their film characters to life on stage -- with some pointing out the similarities to the Oscar-nommed movie.

"Lady gaga pulling bradley cooper on stage to sing shallow with her just like jack did with ally in a star is born. perfect cinematic parallels," wrote one fan on Twitter.

Fans are also *extremely* into the sizzling chemistry the two actors clearly shared during the electricity-charged performance.

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The performance was part of Lady Gaga's Las Vegas residency at the Park MGM -- but has also been tipped as a warm-up for the Oscars.

With "Shallow" nominated for Best Song, the pair will perform the track live at the Academy Awards in LA next month.

While it's normally expected that all Best Song nominees perform at the Oscars, this year only two songs have made the cut.

Variety reported last week that Kendrick Lamar and SZA's "All The Stars" from Black Panther and "Shallow" will get performed live.

Main Image: @YouTube/@GagaDaily