Leach had spent four hours at the Club 215 topless bar in Colton on Feb. 7, leaving just before 2 a.m.
When he was stopped, Leach was riding on the rims of his city car with no lights and no idea where he was or where he was going.
Phillips said he chose to drive Leach home after reaching that decision with Deputy Chief John De La Rosa.
De La Rosa, who has been acting chief since Leach retired, will also retire July 23.
Leach pleaded guilty to DUI after the California Highway Patrol determined he had 11 drinks before he drove.
LAPD Deputy Chief Sergio Diaz has been named to take over the Riverside Police Department on July 1.