Fans attending the Saturday night performance of Lady Gaga’s Enigma show in Las Vegas received a special treat when her “A Star Is Born” director/co-star Bradley Cooper joined her onstage to close out the show with a surprise duet of the film’s hit song “Shallow”.

According to Variety, Cooper was in the audience enjoying the show before he shocked fans by jumping onstage for the final number.

“I even got you in-ears,” Gaga told Cooper after the two embraced, describing the earphone-like monitors used onstage.

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“I can’t hear anything,” he joked, telling the crowd, “Hello Vegas,” before singing his verse in the Oscar-nominated song.

After their performance, Gaga’s backup dancers took their bows, with Cooper joining them. “Bradley, thank you,” said Gaga, with Cooper then tossing his baseball cap into the audience.

In addition to the video above, here’s more fan-shot footage of this amazing onstage moment: