The 51-year-old former Top of The Pops host claimed she heard two women “killing each other” in her street prompting her to run out of her flat and intervene on Saturday night.
She told her Twitter followers: “Please remind me when two women are fighting outside my home don’t go out and try and make peace. At home now with a punch to the jaw. Got to love London.
“Just ran out when two girls were killing each other in my street. Managed to break it up but one decided to hit me. Still standing.
“It was two girls off their heads. I just wanted to calm it down as it was upsetting the neighbours. Just wanted to keep the peace.
“Glad I jumped in as it was looking bad. A punch to me was better than what they were doing to each other.
After followers expressed their concern for Porter’s wellbeing, she replied: “Totally fine. Bit shaken but all good. It’s all sinking in. Blinds down.. may stay a few days indoors.
“I’m Scottish. I can take a sore jaw. Just wish the world was a better place.”
It is unclear whether the fight was reported to the police.
She posted a gif of Bruce Lee, adding: “But…. Today is a beautiful day and it was a sucker punch. No harm done. I didn’t really feel it. Being Scottish and all.”