Johnny Manziel was involved in a fistfight at a fancy Hawaiian resort the night before his friend's wedding, TMZ Sports has learned ... but the QB insists he wasn't the aggressor.
Here's what we know ... Manziel was at the Four Seasons Resort on the Big Island on Friday night when he got into it with another wedding guest.
We're told things had been heated between the guys for a while -- but it all came to a head at the rehearsal dinner.
Sources connected to Manziel tell us the QB felt like he was being hounded by the other man.