The altercation between Barnes and David Patterson Jr., who was previously married to Anansa Sims - the daughter of former model Beverly Johnson - took place at 3.40 pm on Sunday prior to the Niners' 12-19 win at Levi's Stadium, according to TMZ.
Footage shows Barnes, an ex-NBA journeyman who last played for the Golden State Warriors, spitting on Patterson - a former NFL defensive tackle - though tensions boiled over afterwards when a group of fans had to separate the two men following an exchange of insults before both parting their own ways.
Check out the clip: