A day after Jimmy Fallon and Billy Joel brought down the house with a performance of The Rolling Stones' "Beast of Burden" on "The Tonight Show", they teamed up again at Madison Square Garden.
Fallon made a surprise appearance during the Piano Man's monthly concert, taking the stage wearing a Rangers jersey.
The pair again sang a Stones hit, this time belting out "Start Me Up" to the sell-out crowd. One fan posted a video where Fallon asked, "Do you know any Michael McDonald?"
The pair also sang a rendition of "The Lion Sleeps Tonight."
During Joel's appearance on Wednesday's "Tonight Show", the rocker mentioned that he'd like to have Fallon on the stage at the concert.
"You coming?" Joel asked, referencing Thursday's show. "So we'll do something on stage."
Fallon responded, "Really?"
When Fallon suggested the pair do a duet, Joel said, "Whatever you want to do, we can do it all."
Thursday's show was the latest in Joel's residency at the World's Most Famous Arena, which began in 2014.