The Friends stars will compete on the Sept. 20 episode of Celebrity Name Game

Credit: Jeff Kravitz/FilmMagic

Lisa Kudrow and Courteney Cox probably know more fun Friends facts than most other people, but that apparently doesn’t mean they win every game that centers around their hit NBC sitcom.

The real-life pals will compete against each other on the Sept. 20 episode of Celebrity Name Game, but PEOPLE has an exclusive clip of the actresses playing a bonus round together that is all about Friends.

In the bonus round, Cox, 52, tries to get Kudrow, 53, to guess as many of the Friends-related clues as she can.

“Where we had coffee.” Easy. Central Perk.

“We had lunch with her every day. She was on the show.” Jennifer Aniston. Duh.

But one question trips the pals up.

“He was across the way. We would look at him through binoculars,” says Cox.

“Naked Ugly Guy?” asks Kudrow, who inverts the first and second name of their legendary on-screen neighbor.

“Ross?” Kudrow guesses in desperation, naming David Schwimmer‘s character, who did move into Ugly Naked Guy’s old apartment in a later season.

Kudrow and Cox eventually get the answer worked out but the buzzer sounds just as Cox is doing an amazing impersonation of Schwimmer as Ross.

Cox and Kudrow’s episode of Celebrity Name Game airs Sept. 20. Check local listings.