A Westborough teenager was pinned inside a car that was wedged under the rear of an oil delivery truck on South Street this afternoon, Westborough Police say.

Zachary Diamond, 17, of 27 Cook St. "suffered a medical issue" while driving a 2001 Lexus south on South Street around noon, the investigation by Officer Jeffrey Keaveney showed, Police Chief Alan Gordon said in a press release today.

Diamond then lost control of the car and "ran into the rear of the truck which was proceeding in the same direction," near 132 South St., Gordon said. The 2005 Freightliner owned by Al's Oil in Shrewsbury was driven by Alfred Perron, 37, of 2 Laurel St., Oxford.

Westborough firefighters extricated Diamond from the Lexus using the Jaws of Life cutting tool, Gordon said.

Paramedics from the fire department treated Diamond at the scene before transporting him to UMass Medical for treatment, Gordon said. Diamond's injuries were not life threatening, the police chief said.

Motorists were diverted away from the accident scene for about an hour while firefighters assisted Diamond, Gordon said.