The clip shows a Chinese martial artist who is known as @mosstacx on Instagram, where he has a following of more than 38,000 fans.
In the footage, he can be seen showing the strength of the cement block by standing on it, bouncing up and down several times.
The martial artist - who is based in Meixian District, Meizhou, Guangdong Province - then leans it upright against another block, before practicing his hit and measuring the distance with his first.
After a few trial runs, he suddenly snaps the brick in half from close-range, before showing the clean break to the camera.
The video was shared on Reddit, where it's been upvoted more than 93,000 times.
The thread also has thousands of comments, with many people saying just how amazing the slick move was.
"His hand was like an explosive," one person wrote.
Another viewer said: "Smooth operator. Like the hot knife in butter."
A third added: "Jesus Christ, I could barely see the frame of this punch. I wonder how much time he spent training on this."
But not everyone has been as easily impressed, with some arguing that the video 'looks fake' in some way.
One Reddit user asked: "Hasn't anyone else noticed the hiccup in the footage right at the snap. The only hiccup in the footage. Even if he did a full punch it's impressive. But this is edited for sure."
Others shared their theories about what was going on, with someone saying: "The speed of this is insanely impressive, and I don't want to take anything away from this guy, but... Isn't this just pretty simple physics? Non reinforced cement / concrete is quite brittle.
"The part that he breaks is unsupported on the other side while the rest of the length is. The insane speed that he does it makes the small block on the bottom act as kind of a vice holding it in.
"I think anyone of his strength (he is clearly a buff dude) could do this, though certainly not at the speed he does. Just as a note, I am no materials chemist of physics person, so I could be completely wrong."
Another viewer claimed the clip wasn't edited, but was 'still more [or] less a trick', with the 'weak brick being snapped in half, not shattered, once it hits its elastic limit'.
"You can see how he carefully DOESN'T stress the entire thing before hand," they wrote.
"What he's doing is snapping the brick at a weak point over the large stone in the back. Ever drop a brick and have it land halfway across another brick? They f***ing explode when they hit a hard edge, oddly enough, kinda like glass."
They added: "He's still strong as f***, probably, but this is literally a 1000 year old street magic trick, and a small part of Tae Kwon Do, but TDK is honest about it. The main reason, is because it's not even about strength, but SPEED of the hand.
"Moving your hand that fast generates about 2500 newtons of energy. Then, instead of striking the brick, you strike THROUGH the brick at a pre-determined point of vulnerability, pushing it forward to flex it, eventually snapping the top off over the other stone in the back."Featured Image Credit: Instagram/@mosstacx