NBA Star Rudy Gay [Video] -- I Bet I Can Dunk on 25 Foot Hoop

MTV star Rob Dyrdek has a 25 foot basketball rim hangin' at his legendary Fantasy Factory indoor skate park ... and last night, NBA superstar Rudy Gay decided it needed to be DUNKED ON.

TMZ has learned ... Gay was at the downtown L.A. skate spot Wednesday shooting a promo video for the Young and Reckless clothing company, when he noticed the hoop ... suspended 25 feet above a foam ball pit.

We're told 6'8" Gay -- who signed an $85 MILLION contract with the Memphis Grizzlies last year -- eyed up a platform near the rim ... and then BET Rob's cousin Drama he could leap off the ledge and slam it home.