Kobe Bryant took it all the way back to 1992 Monday night ... busting out a slam poem about the legendary Steve Urkel from "Family Matters" -- and he kinda killed it.

The Mamba delivered his performance on "The Tonight Show Starring Jimmy Fallon" -- and with a soft bongo beat in the background, Kobe waxed poetically about Steve vs. Stefan.

He even dropped a "Did I Do That?"

Hopefully, we'll get a follow-up performance next week about Cody Lambert from "Step by Step"?