The massive Overeem brutalized Edwards with power punches, knocking Edwards down three times to end the fight emphatically.
"I hope you enjoyed my fight," Overeem said afterward. "I fight for the fans. You're awesome." Overeem also dedicated the fight to someone he knew who was killed in action in Afghanistan.
When Overeem first made the transition from MMA to kickboxing, he wasn't expected to become one of the sport's truly elite fighters. But he absolutely is, and he showed that once again in the ring against the Australian Edwards, who's a tough fighter but was absolutely no match at all for Overeem.
"I was very confident going into the fight," Overeem said. "My training camp was really professional and really hard. I trained like an animal so I built a lot of confidence because of that. I felt like I could finish it in the first round and I did and so it was a good fight."
Overeem had good things to say about his fallen opponent.
"He was a strong guy," Overeem said. "I could feel his power in his punches. I knew he had the fastest tournament win so I knew I had to watch his power. Once I had a chance to finish the fight, I did."
Although American MMA fans may be disappointed that Overeem won't enter the cage any time soon, every fan of combat sports should respect what he's doing in K-1. He's one of the sport's best fighters and biggest stars, and he's probably the most significant threat to prevent four-time champion Semmy Schilt from winning a fifth time.
Overeem will be back in the K-1 ring at the Final 8 in December, and although Schilt is the clear favorite, it's tough to bet against Overeem.
(MMA FIghting's Daniel Herbertson contributed to this report from Seoul.)