Olivia Rodrigo sings with Billy Joel in surprise performance at Madison Square Garden

Olivia Rodrigo was in a New York state of mind.

The Grammy-winning pop star who references Billy Joel in her hit “deja vu” made a surprise appearance Wednesday at the Piano Man’s concert at Madison Square Garden.

Rodrigo, 19, sang “deja vu” while Joel played the piano, then sang alongside him as they performed his hit “Uptown Girl.”

In “deja vu,” Rodrigo references an ex who is repeating their traditions with a new girlfriend, singing, “I’ll bet that she knows Billy Joel. ‘Cause you played her ‘Uptown Girl.’ "

Wednesday’s concert marked the 82nd show in Joel’s monthly residency at the Garden.

He resumed his performances at the famed New York City arena last November after the COVID-19 pandemic paused the residency for a year and a half.

Rodrigo won three Grammys this year, including best new artist, on the strength of her 2021 album “sour,” which also included the hits “good 4 u” and “driver’s license.”

Joel is a six-time Grammy winner, including receiving a legend award in 1991.