Boxing star Jermell Charlo is REALLY confident his guy Errol Spence Jr. will handle business and remain undefeated on Saturday ... telling TMZ Sports he's putting a $25,000 bet on The Big Fish to beat Terence Crawford.
After years of back and forth, Spence and Crawford are FINALLY slated to throw hands in the ring at T-Mobile Arena in Las Vegas on Saturday ... and it's clear Charlo -- who trains at the same gym as Errol -- has no doubt in his mind who will have their hand raised at the end of the epic matchup.