Fallon went to Hollywood to host 'Jimmy Kimmel Live!'
Kimmel flew to New York City for 'The Tonight Show.'
Throughout the show, they checked in with each other from across the country.
Kimmel interviewed Hugh Jackman and Bridget Everett.
Fallon interviewed "Matt Damon," Justin Timberlake and Kimmel's Aunt Chippy.
Red Hot Chilli Peppers appeared as a musical guest on both shows.
Fallon and Kimmel said they have been talking about the prank since April 2020.