U2 closed out their eight-concert stand at Madison Square Garden on stage last night (July 31) with Bruce Springsteen. Watch as a surprised crowd cheers them through collaborations on two songs, U2's "I Still Haven't Found What I’m Looking For" and Ben E. King's classic "Stand By Me."

Bono earlier hinted at the rock and roll summit to come when he inserted a few lines from Bruce Springsteen's "Hungry Heart" into the U2 song "Beautiful Day." An extra mic was later brought on stage as the group concluded "Where the Streets Have No Name."

Bono introduced Springsteen with some personal remarks about his profound influence on U2, and thanked him for taking over at a benefit concert when Bono was sidelined in a scary bike accident. "Earlier, when I busted myself up here in the city, we had a gig in Times Square for Red and this man showed up and delivered," Bono said. "The chairman, the Boss. Mr. Bruce Springsteen."

Springsteen also sang "I Still Haven't Found What I'm Looking For" during that December 2014 fill-in show at Times Square. He'd also sang a duet on the same Joshua Tree track both at U2's Rock and Roll Hall of Fame induction ceremony back in 2005, and at the hall's 25th anniversary concert three years later.

The Boss joined a long list of special guests as U2 crossed the U.S. – including Paul Simon, Lady Gaga and Jimmy Fallon, among others. U2 heads to Europe in the fall, beginning 34 shows there on Sept. 4 at Torino, Italy.

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