Facing an angry and incredibly powerful Brazilian in Patricky Freire, Alvarez got off to strong start, dropping Pitbull with his first big punch.
Of course, Alvarez is known for getting hurt in his fights and he didn't disappoint, getting popped by Pitbull as he closed in for the kill and was put on wobbly legs.
Freire couldn't finish either and both men traded clinch attempts, leg and body kicks as well as punches for nearly the remainder of the round.
That's when it happened.
With less than 10 seconds remaining in the round, Pitbull had his back to the fence and Alvarez threw a picture-perfect head kick which connected just as Pitbull leaned to his left and slightly ducked down.
The Brazilian went down like a sack of potatoes.
An elated Alvarez jumped the fence, embraced his wife cageside and then ran nearly to the top of the stairs of the Caesar's Windsor arena.
This was the final fight of Alvarez's Bellator contract so he'll be a free agent for whoever wants to have him. With a performance like that, though, as well as his recent first round stoppage victory against Shinya Aoki, he'll likely be in high demand.
Do you think he's earned it?