Mario Williams' baby mama is going to bat for the ex-NFL star ... she says she wants his charges dropped -- this despite him allegedly breaking into her home and wildly yelling at her last month.
Mario -- the former No. 1 overall pick in the 2006 NFL Draft -- was arrested back on Aug. 20 after cops say he made a copy of a garage door remote and illegally entered his baby mama Torie Porter's Texas home.
TMZ Sports obtained video of the standoff that happened when Porter confronted the 6-foot-7, 290-pound former pass rusher at her garage door .