In a parody of Whitney Houston's "Greatest Love of All," the Late Late Show (and recent Tony Awards) host began crooning about his love for the star, who is due to take the West End stage when Sunday in the Park With George opens in London next summer.
Shortly after, Gyllenhaal himself appeared on the studio balcony to duet with Corden. By the finale of "The Greatest Gyllenhaal of All," the two were surrounded by ribbon dancers and were making homages to aforementioned Maggie.
Watch the video above.
Prior to starring alongside Annaleigh Ashford in London's Sunday in the Park With George, Gyllenhaal will return to Broadway in Sea Wall/A Life, a double-bill of monologue plays co-starring Tom Sturridge. Previews begin July 26 at the Hudson Theatre.