Comedienne (and upcoming contestant on “Celebrity Apprentice”) Lisa Lampanelli made her first-ever visit to the set to “Late Show with David Letterman” a memorable one, quickly initiating a feud with Paul Shaffer.

Apparently Lampanelli has a long memory as a regular participant in celebrity roasts, and recalled that Shaffer made a quip about Lampanelli’s body parts during a roast of Chevy Chase. The insult apparently stung, as Lampanelli unleashed a barrage of roast-worthy jokes at Shaffer’s expense, going as far as to compare him to Michael Jackson’s chimp.

Watch their exchange in the clip below…