It happened in the 1900 block of Evergreen near Griggs just after 7am.
The boy's mother left the child in the car, walked into the Little Bo-Peep daycare for just a moment, then came out to see someone taking off in her vehicle.
The boy was let out of the car just blocks away.
A man heard screeching car tires, then saw the boy outside and called police.
"He looked like he was in a dream, kept looking back and forth and was looking around and at that point, I said, what's going on," said witness Jesse Martinez. "My wife started talking to him and he started crying. Come to find out he was asleep in the backseat and wasn't aware of anything until the guy drug him out."
The suspect, who remains on the run, is described as a Hispanic male in his 20s with black hair and a light-colored mustache. He was wearing a peach-colored shirt. The vehicle was recovered a short time later.
If you have any information in this case, you're asked to call Houston police.