The officer was traveling east on Golden Gate Avenue approaching Van Ness Avenue at about 7:30 p.m. when another vehicle, also heading east, attempted to cut in front of him, San Francisco police Sgt. Wilfred Williams said.
To avoid a collision with the other vehicle, the officer crashed into the ground, Williams said.
He was taken to a local hospital to be treated for non-life-threatening injuries.
The driver of the other vehicle, who remained at the scene and provided a statement, was cited for making an improper lane change, Williams said.