Stephen Colbert on Late Night with Jimmy Fallon (NBC)

A man of Jimmy Fallon’s word, Stephen Colbert returned to “Late Night” Friday to sing a rousing rendition of “Friday.”

Last week, Colbert made a promise – without Jimmy’s permission – that Fallon would donate $26,000 to his charity. Fallon one-upped him this week, vowing that if he could raise the funds, Colbert would come back to perform the hit Rebecca Black tune. On Wednesday, Fallon surpassed the $26,000 mark, and the bet was on. (As of Saturday, donorschoose.org/falloncolbertproject was up to $64,133.)

Watch Colbert, decked out in a tuxedo, perform with an auto-tuned Fallon, The Roots, Taylor Hicks(!), and the Knicks City Dancers: