Errol Spence says anyone who thinks Shawn Porter can't beat him is DEAD wrong ... 'cause Spence says Showtime definitely has what it takes to pull the upset.
Porter is a heavy betting underdog in the fight this weekend -- even though Shawn is an elite fighter himself -- and current WBC Welterweight champion.
Most think Spence is too big and skilled to lose the fight, but when we talked to Errol he told us he's not even listening to that talk ... cause he knows how good Porter is.