Mike McCoy was out walking his dog Jake through a neighbourhood in Holiday, Florida, when he started to think that maybe something was going wrong.
Jake was just a little bit away from him when Mike spotted something leap out of the water and grab him unawares.
In Florida, it's a pretty safe bet that it's going to be an alligator.
McCoy told NBC News: "He was in a death roll with that thing."
So, in order to save his pooch's life, he threw himself into the water to try to grab Jake back.
Speaking to ABC Action News, he explained: "I previously read up on my environment and gators. I got around, thumbed him in the eye, picked him out of the water so he couldn't get anywhere until he let the dog go.
"And in the interim he decided, I don't have him, I'll bite you."
Back with NBC, he continued: "Had I not remembered what I read about the alligators, I wouldn't have been able to respond as quickly to help Jake. It was only because I knew what I did that I felt confident to fight the gator off."
The pair were incredibly lucky not to be seriously hurt or worse, but they didn't come out of the encounter with the alligator completely unscathed.
Both he and the dog ended needing stitches.
The alligator was clearly a danger to the local population, too. The attack on Jake took place right beside a school.
That actually helped McCoy in the long run, because the nurse from the school was able to bandage up Mike's wounds after the alligator bit him twice.
Now, the wildlife authorities are out on the lookout for the animal after it attacked both an animal and a human.
They've enlisted the help of a trapper to try to track down and isolate the animal. Exactly what they're planning to do with it after that is anyone's guess.
The smart money would success it's not going to be a whole heap of fun for the animal.
The Florida Fish and Wildlife Commission - who have been leading the search - estimated that the alligator was between seven and nine feet long.
Sounds as if Mike and Jake had a seriously lucky escape.