Lou Diamond Phillips asked the wrong guy for directions early Friday morning ... because the guy he asked arrested him for DWI.
Phillips was driving in Portland, pulled up to a police officer and asked how to get to where he wanted to go. The cop immediately concluded Phillips was hammered and had him take a field sobriety test, which he flunked.
The actor was cuffed and taken to the station, where he blew a .20 ... 2 1/2 times the legal limit.
He's currently being held in jail.