Blachowicz entered the bout ranked No. 4 in the division and riding a four-fight winning streak. Santos was ranked in the No. 6 slot and put an end to the Polish fighter's win streak with a well-timed combination early in the third frame.
In the opening round, both fighters were cautious of the other's abilities. Blachowicz looked to establish his jab while Santos employed a heavy kicking offense. At the end of the first frame, their statistics were nearly identical.
The pace picked up slightly in the second round with Blachowicz putting together combinations and Santos answering with counter shots. Through two rounds, neither fighter had established a clear advantage.
In the third frame, Blachowicz rushed in with a flurry of punches. Santos backed away and fired off a combination that left Blachowicz face-first on the canvas. Blachowicz rolled and covered up but Santos unloaded a series of hammer fists until the referee had seen enough. The end came just 39 seconds into the round.
"I keep on improving. I keep on gaining experience. Each fight is a fight," said Santos following the win. "Last fight I could explode like that. This fight I knew I had to take it easier and use my experience."
"We studied the details. I have a great team with me and that's what happens. When you have a great team behind you, that's the result that you get."
With the win, Santos likely put himself in line to face the winner of champion Jon Jones and Anthony Smith who headlined UFC 235 in Las Vegas on March 2. He holds a win over Smith in a middleweight bout in February 2018.
"The fans will tell who has to be the next challenger. I'm going to Las Vegas to watch Anthony Smith against Jon Jones. If it's Anthony Smith, I'll beat him again. If it's Jon Jones, I'll beat him too," said Santos.