Everything that is great about heavyweight fighting and everything that is wrong with it was on display in the opening five minutes of the main event of UFC Vegas 28 on Saturday between Jairzinho Rozenstruik and Augusto Sakai.

For more than four minutes at Apex, the two big men circled each other cautiously, their right hands cocked but rarely coming out of the holster.

That was the bad part.

But then, when Rozenstruik heard the clapper to signify 10 seconds were left in the round. He exploded and caught Sakai with a left hook and a right hand.

Sakai instantly went down, and Rozenstruik landed two big shots on the ground, forcing referee Herb Dean to shove him off. It was the kind of display of punching power that reminded everyone why the heavyweights are so popular.

No one hits harder than heavyweights and few heavyweights hit as hard as Rozenstruik, who got the second KO at 4:59 of his career. He also stopped Alistair Overeem at 4:59, though that one came with one second left in a fight he was losing.

Coming off a loss to Cyril Gane in February where he admitted he couldn’t let his hands go, Rozenstruik demonstrated the scary punching power that makes him a legitimate championship threat.

“As soon as I heard the clap — tap, tap, tap — I knew it was time to go,” Rozenstruik said.

And once he went, it was over. The finish was no longer than it took him to say tap, tap, tap. He is one of those rare fighters who possesses one-punch knockout power in both hands and doesn’t even need to land cleanly to finish the bout.

Sakai was circling to his right, trying to steer clear of Rozenstruik’s dangerous right hand. But that simply walked him into the left hook, which both Rozenstruik’s coaches and UFC TV analyst Michael Bisping were calling for him to throw.

Once he did it, he was quickly toweling off and heading for home. Sakai was left to pick up the pieces of a second consecutive loss by knockout.

Rozenstruik, who entered the bout ranked sixth in the division, said he hopes to face someone in the top five next.

Full Results:

Main Card (ESPN+, 7:00 p.m. ET/4:00 p.m. PT)

  • #6 Jairzinho Rozenstruik def. #9 Augusto Sakai by TKO via strikes (4:59, R1)
  • #11 Marcin Tybura def. #8 Walt Harris by TKO via strikes (4:06, R1)
  • Roman Dolidze def. Laureano Staropoli by unanimous decision (30-27, 30-27, 30-27)
  • Santiago Ponzinibbio def. Miguel Baeza by unanimous decision (29-28, 29-28, 29-28)
  • Gregory Rodrigues def. Dusko Todorovic by unanimous decision (30-27, 30-27, 29-28)
  • Montana De La Rosa def. Ariane Lipski by TKO via strikes (4:27, R2)

Prelims (ESPN+, 4:00 p.m. ET/1:00 p.m. PT)

  • Ilir Latifi def. Tanner Boser via split decision (29-28, 27-29, 29-28)
  • Muslim Salikhov def. Francisco Trinaldo via unanimous decision (30-27, 30-27, 30-27)
  • Kamuela Kirk def. Makwan Amirkhani via unanimous decision (30-27, 29-28, 29-28)
  • Alan Patrick vs. Mason Jones ends in a no contest (2:14, R2)
  • Manon Fiorot def. Tabatha Ricci via TKO (3:00, R2)
  • Sean Woodson def. Youseff Zalal via split-decision (29-28, 28-29, 29-28)
  • Claudio Puelles def. Jordan Leavitt via unanimous decision (29-28, 29-28, 29-28)