4:50 PM PDT -- Fisher's girlfriend Loni Rae, the alleged victim, told KDVR, "Things just got out of hand and he snapped ... and my entire cabinets are ripped off from my walls. I had my feet up against the wall trying not to let him in, and he busted through the door and he pushed me through the cabinets."
10:45 AM PDT -- TMZ obtained Fisher's mug shot ... in which the rocker appears to be bleeding from a gnarly gash on his forehead.
So far, it's unclear how Edward suffered the injury.
The drummer for the band OneRepublic was arrested in Denver, CO this morning ... after cops say he flipped out in a destructive rage.
TMZ has learned ... Edward Ray Fisher was booked for destruction of private property, disturbing the peace and assault. The details surrounding his arrest are unclear.
According to his booking sheet, the 38-year-old rocker -- who lives in Denver -- is 5'8" and weighs 155 pounds.
Fisher is scheduled to appear in Denver County Court tomorrow afternoon.
FYI -- OneRepublic was nominated for a Grammy in 2009 for their smash hit, "Apologize."
Story developing ...