Vince Young assaulted a woman during a drunken March Madness road trip ... according to the lawsuit she's just filed against the ex-NFL star.
Tiffany Cayo says she and Vince were on their way back from a NCAA Tournament game back in 2014, riding in the same vehicle ... when he reached over and pulled her hair. In the docs, obtained by TMZ Sports, Cayo describes Young as "extremely intoxicated" at the time of the incident.
The suit doesn't say if Vince was driving at the time.
She doesn't detail her injuries, but the hair pull sounds very violent -- Cayo says she's racked up medical expenses, and lost wages as a result of the alleged attack. She's suing for $250k.
We've reached out to Young's rep for comment. No word back yet.