Mr Britton said he raised his chainsaw and met the lion head-on as it pounced - a collision he described as feeling like a grown man running directly into him.
"It batted me three or four times with its front paws and as quick as I hit it with that saw it just turned away," he told the Associated Press.
The wounded animal retreated after Mr Britton inflicted a six to eight-inch gash on the lion's shoulder. Mr Britton was left with only a small puncture wound on his forearm.
"You would think if you hit an animal with a chainsaw it would dig right in," he said. "I might as well have hit it with a hockey stick."
Deadites: Yes. Mountain lions: no.