Fired Ohio State assistant coach Zach Smith just broke his silence on his alleged domestic violence ... saying he NEVER beat his ex-wife.
Zach went on 105.7 The Zone to tell his side of the story ... and says while he was in a "volatile" and "toxic" relationship, he "never committed domestic abuse against her."
As for the photos Zach's ex-wife, Courtney Smith, released showing bruises on her body from the alleged abuse ... Zach said he may have caused them while "defensively restraining her" when situations "got out of hand" ... but insists he never struck her.
Smith also says PLENTY of people at Ohio State knew of the accusations back in 2015 ... saying it was OSU athletic director Gene Smith himself that actually informed him of the claims.
Smith went on to say he doesn't believe he deserved to be fired last month ... and thinks he was only terminated so the team wouldn't have to answer questions about him and the incident.
As for Urban Meyer's role in the whole ordeal ... the head coach admitted to knowing about the 2015 allegations, but lied to the media about them at Big Ten Media Day because he "was not adequately prepared to discuss these sensitive personnel issues with the media."