A Seahawks fan says Marshawn Lynch turned into Beastmode outside of a Seattle bar over the weekend ... smashing his phone during an altercation.
The Hawks supporter's name is Jose Lozano ... and he tells TMZ Sports the incident all happened in front of Xtadium in downtown Seattle on Sunday at around 1:30 AM.
Lozano says he tried to get a pic with Lynch inside of the bar earlier in the night -- but was denied by the Seahawks legend's friends ... who told him straight up, "No pictures.