San Francisco 49ers super fan E-40 and diehard Kansas City Chiefs backer Tech N9ne came face-to-face ahead of their teams' huge Super Bowl matchup ... and luckily, the TMZ Sports cameras were rolling for the whole hilarious interaction!!

The two MCs put their loyalty on full display at NBA legend Shaquille O'Neal's "Shaq's Fun House" event on Friday night ... and there was no shortage of friendly banter.

Our photog asked the two rap greats if there were any wagers going down for the Big Game ... and as you can tell in the clip, they have too much respect for each other -- and their teams -- to risk taking money from their "family."

But that didn't stop them from letting it known where they stand on the contest ... with N9ne pointing out Patrick Mahomes will lead the Chiefs to a second-straight championship ... and 40 giving "Mr. Irrelevant" Brock Purdy his flowers.

E-Four-Oh and Tecca Nina aren't just casual fans -- they've both gotten in the booth to record anthems for their beloved squads ... so no one can accuse them of being fair-weather fans at all.

While the two rappers may have placed their own individual bets on the game -- gotta love their confidence -- it's clear they'll still maintain their respect for each other no matter what the scoreboard says after the game.