Corden opened the bit mock-strumming the weepy James Blunt ballad "You're Beautiful" on acoustic guitar, but the host became possessive over his turf when Mendes posted up nearby and started crooning Oasis' hit "Wonderwall."
"Oh, no – no way," the comedian interjected. "Not on my watch. Me's got to say 'no.' I've been here since 6 a.m., so you and whatever this is can go somewhere else." After an awkward argument, the late-night host attempted to outdo his rival: Decked out in a sparking suit and bow tie, he slid in with a grand piano and howled Jerry Lee Lewis' rock classic "Great Balls of Fire."
This launched a back-and-forth of increasingly ridiculous covers. Mendes responded by triggering Rihanna and Calvin Harris' EDM anthem "We Found Love"; Corden, attached to four dummy singers, fired back by singing Backstreet Boys' "Everybody (Backstreet's Back)"; and an angel-winged Mendes emerged victorious after descending from the heavens with an acoustic guitar and playing his hit "There's Nothing Holding Me Back," with help from a gospel choir.
Mendes, midway through his week-long Late Late Show residency, also performed his stripped-back duet "Like to Be You" with Julia Michaels during the episode. The duo sang to each other while seated on two stools, staring directly into each others' eyes as a solitary camera circled around them.