U2 was joined by pop star Lady Gaga on stage on Wednesday, October 25 during the Irish rock band's ongoing U2:UV Achtung Baby Live At The Sphere residency in Las Vegas.

Bono and Lady Gaga sang two of U2's biggest songs - "All I Want Is You" and "I Still Haven't Found What I'm Looking For" - as well as Lady Gaga's hit song "Shallow," which she originally recorded alongside Bradley Cooper for their Oscar-nominated film "A Star Is Born."

Gaga, donning a black leather jacket and dark sunglasses, could have easily passed as a member of the iconic Irish rock band as she joined them on stage.

The Irish rockers thanked Lady Gaga on social media on Friday for her special performance:

Thank you, @ladygaga.
U2:UV Achtung Baby, Live at Sphere. XII.

📸: Kevin Mazur pic.twitter.com/WHjXNJ5X70

— U2 (@U2) October 27, 2023

Introducing Lady Gaga on Wednesday night, U2 frontman Bono described the 13-time Grammy winner as "the most audacious, vivacious woman in any room she’s ever in."

"Would you welcome to our turntable, the divine - the divinyl! - Lady Gaga," Bono said during Wednesday's performance. 

In the middle of their performance of "I Still Haven't Found What I'm Looking For," Bono described Gaga as the "vestal virgin of Las Vegas."

You can see a fan's recording of U2 and Lady Gaga performing "I Still Haven't Found What I'm Looking For" in Las Vegas here:

Another fan shared this video of U2 and Lady Gaga performing "All I Want Is You" and "Shallow" to great acclaim:

As Variety notes, Lady Gaga was the first special guest brought on stage for a duet during U2's much-hyped residency at the brand-new Las Vegas Sphere. Only time will tell if other musicians will follow in Gaga's lead.

There's plenty of time for more surprises during the U2:UV Achtung Baby Live At The Sphere residency in Las Vegas as a slew of new dates have recently been added, extending the Irish rock band's run through February.

This wasn't the first time U2 was joined by Lady Gaga. Back in July 2015, they teamed up for a duet of the U2 song "Ordinary Love" during the Irish band's concert at New York City's Madison Square Garden.