Cancel Saturday's main event and give Joaquin Buckley the W ... 'cause TMZ Sports has learned viral D.U.S.T. self-defense star, Commander Dale Brown is cornering the UFC star at Fight Night.
And, let's be honest ... he ain't losin' with Commander Brown by his side.
The soon-to-be 14-4 MMA fighter recently hit up Brown -- known for his awesome/viral self-defense videos -- and actually travelled to his Detroit Urban Surviving Training school last month to learn some moves.
FYI, Brown's popularity exploded after Odell Beckham Jr.