"L.A. Dodgers 1st baseman James Loney has dodged a MAJOR bullet ... because prosecutors have rejected the DUI case against him ... even though he allegedly acted like a complete maniac on the night he crashed his Maserati.

TMZ broke the story ... Loney was popped in L.A. back in November after colliding with a Toyota around 6 PM and then careening into 2 other vehicles.

According to the police report, the officer on the scene claims Loney's behavior was incredibly bizarre ... noting the athlete "exhibited eyelid tremors and his shirt was soiled and moist from perspiration, from his armpits down to his waistline.""