The black bear scarpered quickly after Riley slammed in to him.
Remarkable footage shows a huge bear being chased away by a dog less than half its size after it wandered into a residential garden.
The incident, which was captured on surveillance cameras at Mark Stinziano’s home in Hewitt, New Jersey, in the US, happened just after 8pm on July 9.
In the footage, the black bear can be seen exploring the garden and standing on its hind legs to bull down a bird feeder, before the neighbour’s dog, Riley, appears from next door and sprints towards it.
At first, the bear watches the dog approach and it is not until the dog launches itself towards the larger animal that the bear appears to realise it is being targeted, and runs away.
According to the New Jersey state website of the Department of Environmental Protection, black bears are the largest land mammal in New Jersey and they are attracted to urban neighbourhoods by the smell of rubbish.
Riley’s owner, Alan Tlusty, said his dog chases any bear that appears in the garden, and Mr Stinziano said the dog sometimes watches over his children when they are in the pool.
The department recommends residents secure their rubbish to help stop bears being attracted and creating a nuisance.