The officer had been waiting for the traffic lights to turn green at the corners of Mew Way and Jafta Masemola Road on Monday when he witnessed a silver Toyota Yaris driver in front of him being dragged out of his vehicle by two armed men.
Police said the officer intervened and the two suspects fired shots at him.
“The officer shot back, wounding a 24 -year-old suspect in his lower back. The other suspect with the firearm then managed to run away between the shacks, and we are in pursuit of him,” said police spokesperson FC van Wyk.
He said cases of attempted murder, attacks on police and hijackings were registered for investigation.
Van Wyk said the police officer and the driver sustained no injuries.
The injured suspect was taken to a nearby hospital for medical treatment where he was placed under police guard.
Independent Police Investigative Directorate spokesperson Moses Dlamini said it was investigating preliminary discharge of a police firearm.
Some motorists who also witnessed the hijacking took to social media, praising the police officer for being brave and saving the driver.
Meanwhile, police are yet to arrest suspects following the killing of former law enforcement officer Nhlangano Mkhize.
Mkhize was shot dead in a suspected hijacking in Khayelitsha last Friday. The city has since offered a R50000 reward for information leading to the arrest and conviction of the suspects behind the incident.
Anyone with information about the shooting can anonymously contact Crime Stop at 0860010111 or SMS Crime Line on 32211. Alternatively contact the Safety and Security Investigation unit at 0214807700.