Shaq was performing at Echostage as DJ Diesel -- when he decided to clown his "Inside the NBA" co-host with a giant projection on the back wall that read, "Barkley Has NO Ring!"

Shaq clapped along gleefully as the place went crazy!

Of course, Shaq and Chuck are really tight in real life -- so, it's all in good fun.

Now, it's on Barkley to get even ...

Of course, it's not the first time Shaq went off on an NBA star in a nightclub -- back in the day, he freestyled the infamous "Kobe, tell me how my ass tastes" verse during his rift with his Lakers teammate.

Both Shaq and Kobe have said they've made up and they're on good terms now.