As Matyushenko was charging in, Gustafsson landed a perfect left jab that leveled Matyushenko, then pounced on him and landed several more punches on the ground before referee Yves Lavigne stepped in to stop the fight.
The fight lasted just 2 minutes, 13 seconds.
"He's a good fighter, I look up to him, but I got the knockout," Gustafsson said afterward. "It was a good punch. It was my day to day. It was my dream to fight in Las Vegas and it was the biggest win of my life."
The 24-year-old Gustafsson is now 13-1 in his MMA career, and he has a good chance of becoming a title contender in the light heavyweight division. Gustafsson has room to get bigger, stronger and better, but he's already plenty good. Matyushenko found that out the hard way.