Neil Patrick Harris interrupted James Corden's The Late Late Show monologue on Monday night to challenge the host to a Broadway riff-off.
Harris said with a serious look, "Your silly jokes can wait, Corden, we have a score to settle and it's about...Broadway."
Joined by the a cappella group The Filharmonic, the two squared off for riff off battle. The two sang hits from classics like Guys and Dolls to Les Miserables and Hamilton.