DENVER - A video of an unfazed house cat staring down a mountain lion as the predator paws at a kitchen window has gone viral, receiving nearly one million views on YouTube in just a few days.

The footage, recorded at a home in the Rocky Mountains in Colorado, shows the fluffy cat sitting on the windowsill and meowing as the much bigger mountain lion looks into the house, its eyes glinting gold in the light.

The video was posted on Sunday and had already been watched more than 945,000 times by Tuesday morning.

It was filmed by Mr Tom Mabe, a Louisville, Kentucky- based comedian, who says the face-off took place during a visit his family made about a month ago to friends who were living in the Boulder area of Colorado.

In the video, the mountain lion repeatedly paws at the window as Mr Mabe can be heard calling his wife to see the face-off. "Is that crazy or what?" he says.

His wife can be heard asking where the kids are, and Mr Mabe jokes that they are "out back", before reassuring her that they are still in bed.

After about 30 seconds, the mountain lion stalks away, pausing on a nearby rocky slope to gaze back at the home.

In the comments posted below the video, Mr Mabe joked that he was hoping to get sponsorship from a double- glazing window company.

He declined to reveal exactly where the video was shot, saying that his friends are trying to sell their home.

It is the second wild animal saga to make headlines in the Boulder area this week.

On Monday, police released photos of a young female moose that had wandered on to the city's main pedestrian shopping area, attracting a crowd of onlookers.

REUTERS