Melissa McGinn says she encountered an “angel” in Johannesburg peak-hour traffic, who saved her from a robber - by driving into him.

“You, sir, were a hero (on Wednesday morning). You saved my life and I was able to come home to my little boy because of you! Thank you! Thank you from the bottom of my heart!!!! I had an encounter today with an angel and I’m so grateful you were there!!!” McGinn wrote on Facebook.

“He waited for me to drive away, he didn’t move his car until I was gone. Thank you so, so much for risking your life for a complete stranger!”

McGinn was driving along the Crown Interchange, from Alberton to Melrose Arch at around 8am, when “someone started hitting a gun on my window, telling me if I didn’t open the window he would put a bullet in my head”.

McGinn told TimesLIVE on Thursday it was the first time she had been held up and she did not look at the man. She was unsure if he wanted her vehicle, as well as her phone.

“I wanted to get out of the car to give him my car. I thought that was what he was after. I opened my window and he hit me with the gun. He pulled me forward and hit my head with the gun and pushed me back.”

The robber then held the gun against McGinn’s temple, and this was when the car rammed into him.

McGinn is unsure how the motorist managed to reach her in the bumper-to-bumper traffic. “He came out of nowhere.”

In her Facebook thread, McGinn wrote: “There was a man in a red car. I have no idea what car. I don’t remember what he looked like or anything, but this man drove into the person holding the gun to my head.

"He saved my life, I didn’t get a chance to thank him but I hope he somehow sees this post.”