It happened in the 1900 block of Sam Houston Parkway East near Aldine Westfield around 2:30 a.m.
The man said a driver in a Cadillac CTS fired several times into the man's car, hitting him once in the leg. That's when he crashed into a pillar.
A deputy arrived at the scene and applied a tourniquet to the man's leg, ultimately saving his life, according to first responders.
"He was bleeding pretty profusely from one of his legs," said Lt. Christopher Bruce.
The shooter remains on the loose.