Police are hunting a gang who tried to steal £50,000 worth of motorbikes from a showroom in Croydon, south east London.
CCTV footage shows six men arrive on scooters before two of them walk into the shop and attempt to wheel out two Ducati Panigale bikes worth £25,000 each.
When In-Moto shop worker Paul Read, 35, saw what was happening he tried to hold on to the bikes and wrestle the men to the ground.
The fight spilled-out into the street where sales manager Adrian Couzens, 29, saw what was happening and ran over to help, pushing one of the gang off his scooter.
The gang retaliated with claw hammers, iron bars and bolt-cutters which they used to attack Mr Couzens and three other men who confronted the gang.
Mr Couzens said: "My first thoughts were just to get over and help. It was instinct for me. But when I saw the hammers and iron bars I realised it was more serious than I first thought."
"One of the gang smashed the window of the showroom with a claw hammer, which made me back off a bit."
Pictures caught on the shop's CCTV cameras show Mr Couzens grapple with one of the gang and put him in a headlock before pushing him to the ground twice.
"The police asked if I was brave or stupid," he said.
"I'm a dad of two, my youngest being 15 months old. If they had smacked me around the head with a hammer it could have been a lot worse.
"Last year we had problems with gangs trying to steal motorcycles. It's happening to lots of other dealers in Croydon and Kent and we're fed-up with people like this who think they can get away with it."
Despite the efforts of shop staff the gang were all able to escape.