MashGet

NEW YORK - Paul McCartney sat in with Billy Joel last year at the last concert ever at Shea Stadium, and Joel returned the favor on Friday, joining the ex-Beatle at the first concert at the building that has replaced Shea, Citi Field.

Joel, taking time out from his own tour with Elton John, took the stage during the encores, singing and playing muscular piano licks on the old Beatles song, "I Saw Her Standing There." The two Rock and Roll Hall of Famers high-fived before the song, and hugged after it.