The crash was reported at 6:28 a.m. near Mariposa and Indiana streets.
The driver told police he was exiting the highway at Mariposa Street when he lost his brakes, police spokesman Officer Albie Esparza said.
He tried to swerve but was unable to avoid a Mini Cooper that was stopped in front of him, and his car smashed into it and overturned, Esparza said. He was not injured.
Two people inside the Mini Cooper were taken to a hospital, one of whom had to be extricated from the car, Esparza said. Their injuries were not life-threatening.
The off-ramp was shut down while the crash was investigated.