Winston and his best friend, a 15-year-old chiweenie named Mijo, live in Evergreen, CO, with their humans, Sarah Moore and Lindsay Golden.

Last week, the besties slipped out a door that was accidentally left ajar, and ran right into the path of a prowling mountain lion. The big cat instantly snatched up Mijo in its powerful jaws and made off with him, with Mijo "screaming" out for help (it was probably more like a howl, but its owners called it a scream, so we'll go with it).

That's when Winston jumped into action.

Instead of cowering in the face of the wild cat, the dog charged it.

And when the mountain lion took off with his buddy Mijo in its clutches, Winston immediately took chase, barking and yelping for the big cat to give up its prey.

Amazingly, it worked.

The mountain lion eventually dropped the chiweenie from its mouth and ran off empty handed.

Good boy, Winston!

Mind you, Winston only weighs 20 lbs. Mountain lions can grow to be up to 140 lbs for a female and up to 220 lbs for a male. And they can run up to 40 miles per hour, and can leap up to 40 feet in a single bound.

Fortunately, for Mijo, friendship trumped fear.

"This is his best friend, so I'm not surprised that when he was screaming, that he chased after him," Moore told 9 News.

"He's got a lot of heart … A 20 lb dog with the courage of a 200 lb dog," she added.

Even though Mijo lost an eye and suffered some neurological damage, he's alive and recovering nicely.

BONUS! Here's some Chiweenie Trivia for you:

A Chiweenie — also known as a choxie — is a cross between a Chihuahua and a dachshund. This designer breed is spirited and loyal, packing a big attitude in a small body. Also, affectionately known as weeniehuahuas, Mexican hot dogs and German tacos, Chiweenie puppies and adults both make great watchdogs.

Weeniehuahuas! Mexican hot dogs! German tacos! Beyond the rescue, this story was worth it just to learn these names!