Hattie Atkinson Smith, 27, said the huge bird of prey - which has a 6 ft (1.8m) wide wingspan - latched onto her ponytail during her daily workout on a riverside path.
The data scientist said she’d been out jogging at 6.10 am close to Norwich City's Carrow Road football stadium when she had felt a “hand” on the back of her head.
But when she'd turned around, she noticed to her horror that a “massive bird” was attacking her head before she shook it off and then “sprinted” away to safety.
Hattie, who was unhurt, later looked up the raptor on the internet and realised it was a missing Eurasian Eagle-owl, which has been on the loose in Norwich for some time.
She thinks the bird may have mistaken her ponytail for rodent.
Speaking after her ordeal, she said: “I think it thought I was an animal and tried to eat me - it was so weird!
“It was just so big – that was what was scary – and I’ve never seen a bird as big as that in the wild, not in a zoo!”
“I sprinted away because I was obviously a bit scared it would try again.”
Hattie said she had her headphones in and was minding her own business on a cold morning last Monday (March 7) when the raptor attacked.
She said: “It was morning around 6.10 am, and I was going for a run before work.
“My head was down, and I had my headphones in, and I was not really taking much in around me.
“Then I felt something on my head, and it felt like a hand that went down over my head.
“I looked up and there was just this massive bird that had obviously come down.
She added: “I’d say the wingspan was coming up to as tall as me – it was really big. I’m 5ft 5. I thought the wingspan was huge!”
“My hair was up in a ponytail, so this is why I think it might have thought I was a rodent or something.”
Hattie said when she finished her run, she tried to identify the bird of prey online, and realised it wasn’t a species native to the UK.
She said: “I got a really good look at it, and when I finished my run, I started googling birds of prey.
"I was sure it was a bird of prey as it was so big, and it had the hooked beak and stuff.
“Its feathers were two different shades of brown, and then it had these feathers above the eyes that kind of poked up.
“I thought it was a Eurasian eagle owl from just the pictures on the internet.
“But I saw it wasn’t native to the UK, so I googled Norwich eagle owl, and it came up with all these articles about it.
“So I thought it must have been this owl that people are aware of and have been in Norwich.”
Hattie said she hasn't reached out to the bird's owners, and despite her ordeal, she was quite glad that her attacker turned out not to be human.
She said: "I’m kind of relieved it wasn’t a person."
The owl, called Alfie, has been prowling the streets surrounding the home of Norwich City - ironically nicknamed the Canaries - with residents regularly reporting sightings.
It’s likely that the owl, which is among the largest of its kinds and is native to parts of Europe, Asian and Northern Africa, escaped from captivity.
It has distinctive pumpkin-orange-coloured eyes, as well as feathery ear tufts, making an incredible striking bird of prey.