The collision happened around 2 a.m. at the intersection of Colorado and Sierra Madre boulevards.
Police said a white SUV was heading southbound on Sierra Madre when it smashed into a black Honda heading east on Colorado, pushing it over a median and severing a sprinkler main.
The driver of the Honda was pronounced dead at the scene. The coroner's office identified him as Abeme Minuta, 24, from Pasadena.
Witnesses said the driver of the SUV got out, but not to help the other man. Instead, the driver fled the scene on foot and police are still looking for that individual.
Officers are checking surveillance footage from businesses in the area.
Police are investigating the cause of the crash.