This is the moment a job attacked a dog trainer as he walked his greyhound to the trap at a racecourse.
A shocking video shows the fuming racing fan running up to the handler from behind before jumping on his back at Crayford Greyhound Track in South East London.
Cops have now arrested the thug on suspicion of causing actual bodily harm.
The clip shows the invader thumping the trainer on the head as his greyhound struggles to take cover.
The thug then knees the trainer in the face while he holds him by the hood of his jumper.
He throws a few more punches before the horrified cameraman pans away from the terrifying scene.
The stadium, which has featured races since 1986, is one of just 20 remaining dog tracks in the UK.
It has raced five days a week and is owned by Ladbrokes Coral.
Racing fans took to Twitter to tell of their shock.
One wrote: "I've never seen anything like this. We need some context ASAP."
Another added: "I was hoping someone else saw this. Hopefully, the bloke is ok."
A third said: "Jesus Christ. Fair play to the person with the two dogs getting the lead and the greyhound out the way ASAP."
A spokesperson for Met Police for comment said: "Police were called at 12.36hrs on Wednesday, 25 January to reports of an assault at commercial premises in Stadium Way, Crayford.
"A man (no further details) was arrested on suspicion of causing actual bodily harm."
A spokesperson for Ladbrokes told The Sun: “This was a deeply unsavory incident and one the police are now dealing with.
"Our prime concern is the well-being of the individual who was the victim of this awful assault.
"We are making sure he is okay, which fortunately he seems to be, whilst also assisting the police with their investigation."
Crayford Greyhound Track refused to comment when approached by The Sun.
