Floyd Mayweather Sr. beat the criminal charge ... but now he's being sued by the woman who accused him of punching her after the 1st Canelo-GGG fight last year.
In the lawsuit obtained by TMZ Sports, Marsha Byrd claims she got into a verbal altercation with Mayweather Sr. on September 17, 2017 outside T-Mobile Arena in Vegas ... which she says turned physical.
Byrd says Floyd Sr. dragged her out of his car and repeatedly punched her with a closed fist .