This is the moment a tiny great-gran wrestled with a six-foot-tall thug who came into an antiques shop and tried to sell her a stolen £1,200 bike for £150.
Supergran Mari Parker, 72, knew the bike had been stolen having read about its theft on Facebook and refused to let the thief leave the store with it.
However the un-named male in his 20s returned half an hour later and tried to take the bike back by force.
CCTV footage shows five foot three inches tall Mari in a minute long tug-of-war with the thug outside the shop as she hung on to the bike frame for dear life.
The hooded thief can been seen violently pulling at the bike and even trying to mount it to cycle away but his efforts were thwarted by the determined OAP.
He eventually fled empty-handed and the designer mountain bike was later reunited with its rightful owner.
Gran of eight Mari said today: "I'm sure he must be a bit embarrassed now that he was beaten by a 72-year-old woman."
The incident happened on a Sunday morning at Mari's son, Daniel's, antique shop, Barnsley Antiques Centre, where she helps out part-time.
The man had come into the shop asking if they wanted to buy the bike for £150.
Unfortunately for him, Mari and Daniel had already seen a post about that exact bike being stolen on a Facebook page so they told the man it was nicked and that he must leave it behind.
The man then left the store and, after calling the rightful owner of the bike asking him to come and collect it, Daniel went out on an errand.
However, shortly after the man returned and told Mari he was going to take the bike.
Mari said: "I think he must have watched my son leave and known I was in the shop on my own so he came back.
"He said 'Will there be a reward then?' and I told him no.
"He said 'I'm going to 'bleep bleep' take it back then' and I came out from behind the counter and told him he wasn't.
"He had hold of one side of the bike and I had hold of the other and we were then in this tug-of-war.
"He pulled me outside and we were fighting in the street.
"A couple of customers came out to help but I was worried about what would happen with them so I told them to leave it to me and that they should call the police.
"But I refused to let go.
"I knew a young boy was coming back for his bike and I couldn't tell them we didn't have it.
"Thinking back now I'm not sure I'd have done that if I'd have really thought about it, but it was all a spur-of-the moment thing and it happened so quickly."
Mum-of-three Mari maintains her strength comes from play boxing with two of her grandsons.
She said: "If you're not fast enough for them you get a black eye."
And now the bike has been re-united with its 13-year-old owner, Luke Hodson, much to everybody's delight.
Mari added: "My son rang the family to say he had their bike and they were due to come and get it.
"In that time my son went out and the man came back.
The ex-market trader said her hands were bleeding afterwards and her muscles were aching for a good few days.
And although she doesn't work out Mari does consider herself fit and healthy: "Put it this way," she said, "I don't sit down."
Mari works in the shop for her son Daniel, 44, up to four days a week.
She said: "We do get a lot of undesirables coming in here and we have done this before. We will always try to call the criminals out if we can."
Luke Hodson had his bike stolen just the week before by a man, who was not the same man who came into the shop, who shoved him from his bike on a main street in Barnsley, in broad daylight and took it from him.
The Lapierre X Control 310 full suspension mountain bike was bought for Luke by his uncle just two months earlier with money inherited by the loss of his father - Luke's granddad.
His other grandad, Brent Stables, 60, said: "Luke didn't think he was going to see the bike again.
"He is over-the moon to get his bike back. It is his pride and joy. He rides it everywhere.
"I think Mari was wonderful, for a 72-year-old to do that is so heroic.
"They could have had a knife or even pushed her over. she is so brave. My admiration knows no bounds."
South Yorkshire Police confirmed: "Police received a report about a suspected stolen bike being brought into the Barnsley Antiques Centre, Doncaster Road,'
"The business owners, suspecting the bike was stolen property, kept the bike on the premises to return it to its rightful owner.
"It is reported that a man entered the shop to try and take the bike back, but was prevented from doing so.
"A 23-year-old Doncaster man was arrested in connection to this matter and interviewed by officers.
"The bike was returned to its rightful owner, who did not wish to pursue a prosecution."
The incident happened in October last year.