UFC's Dominick Cruz: Urijah Faber's Chin Looks Like a Butt

UFC bantamweight champ Dominick Cruz says Urijah Faber's chin looks like a butt -- so, we decided to see if he could seriously tell the difference in a game called, "Butt ... or Urijah Faber's Chin."

Cruz appeared on the "TMZ Sports" TV show (airs Friday night on FS1) -- and played the game ... and did surprisingly well!!

Here's a teaser clip -- but make sure to watch the WHOLE THING on the show tonight ... it's pretty hilarious.