Wednesday night, the Late Late Show host got himself into a bit of hot water when he argued divas of the past have a leg up on divas today.
"They didn't have Instagram—they just had sass, voice, songs," he told his audience.
However, the claims did not go unchallenged. "I heard you've been telling people that divas back then are better than divas today," Lovato said as she surprised the audience and came out on stage.
Refusing to accept the argument, the singer offered Corden a proposal. "Why don't we just settle this tonight?"
With the help of a cappella group Level, Lovato launched into Adele's "Rolling in the Deep," which was met with thunderous applause.
Next, it was Corden's turn and he opted for Tina Turner's classic, "River Deep, Mountain High." However, his opponent was a harsh critic. "Wow, that was terrible. Just really awful. Bad," she shot back.
"You better watch your mouth," he told her. "You know what you need, little lady? You need a little respect." So, he gave her some in the form of Aretha Franklin's signature tune.
Lovato took him to task with Katy Perry's "Roar," but when he called her out for not performing any of her own songs, she launched back with "Heart Attack," complete with a mic drop. It was just enough to secure the victory.
"Can you pick my mic up...bitch," she told Corden—and he reluctantly did.
While Corden admitted that she proved him wrong, he worried that ultimately, he just is not a good enough diva. However, Lovato assured him that he was the "best damn diva I've ever seen."
For the grand finale, they brought the house down with a duet of Gloria Gaynor's "I Will Survive" and all was well in diva land.