It happened at about 11:30 a.m. Saturday in an alley on the West Side.
According to police, four officers saw a man sell drugs on the corner of Chicago and Springfield Avenues and tried to approach him.
The man ran into an alley, jumped into a van and hit the gas.
The squad car blocked his exit and as he swerved to get away, He nearly pinned down an officer.
That's when the officer jumped onto the hood of the van and fired three shots.
The officer suffered a foot injury and was taken to the UIC Medical Center.
Police recovered ten rocks or bags of cocaine from the van.