UFC 143 openers: ‘Wonderboy’ Thompson posts the KO of the Night

LAS VEGAS -- There aren't too many karate practitioners succeeding at the highest level of mixed martial arts. Meet Stephen "Wonderboy" Thompson. He might change that.

A kickboxer with over 50 fights, Thompson made his UFC debut a spectacular one at UFC 143. Thompson sized up Dan Stittgen for a few minutes and when his opponent relaxed a bit, Wonderboy landed a nasty roundhouse kick on Stittgen's chin. He was out cold in a split second at the 4:13 mark of the first round.

That's a helluva bar Thompson just set for Knockout of the Night. The UFC awards KO of the Night, Submission of the Night and Fight of the Night bonuses usually good for $65,000. Thompson looks like a shoo-in right now.

UPDATE: Thomson got the award and the $65,000.

It certainly wasn't the fight of the night. Stittgen, also making his promotional debut, never looked comfortable in the Octagon. His strength is supposedly jiu-jitsu, but he never got close enough to Thompson to even attempt a takedown.

"No words can describe how I feel right now. I'm beyond happy to have this win. It's my first win in the UFC and I can't wait to get back out there and do it again. I took my time and felt him out," said Thompson.

Thompson's kickboxing pedigree is impressive. He reeled off 57 straight victories before moving over to MMA in 2009, where he's now 6-0.

Natal's takedowns too much for striker Kuiper

Rafael Natal isn't pretty, but his grinding style was effective tonight against young Michael Kuiper.

Natal scored multiple takedowns in each of the first two rounds and worked top control. That was enough to get a unanimous decision, 30-27, 30-27 and 29-28, in fight No. 2 of the night.

It wasn't easy for Natal, who got blasted and rocked by a Kuiper uppercut just a few seconds into the third round. Kuiper, 22, jumped on top, but Natal (14-3-1, 3-1-1 UFC) used his grappling skills to minimize damage. Kuiper got off some effective body shots, but nothing huge to Natal's head.

Natal admitted to UFC analyst Joe Rogan that "everything went black" for a second after Kuiper landed the big right.

With 2:40 left in the fight, Natal got to his feet. Seconds later, he scored a big slam takedown of Kuiper. Down big in the round, Natal grabbed back control by working side control to a mount where he eventually slapped on a head and arm choke. Kuiper was caught in the submission hold for 40 seconds, but never tapped.

This was the first loss for the 22-year-old Dutchman. Kuiper (11-1, 0-1 UFC) did get the nod in the final round from Patricia Morse-Jarman.

Riddle notches win over gritty Martinez

Henry Martinez has some stones, but it just wasn't enough to get him the win tonight on short notice. Matt Riddle eked out a split decision over the Jackson's MMA fighter, 29-28, 28-29 and 29-28.

"This fight was a war, but it's nice to be back on the winning end again. Henry hit hard and his hands were quick. I was impressed by him and that's why I picked it up in the second and third rounds," said Riddle.

The 5-foot-6 Martinez, who's really a lightweight, put the pressure on for the first few minutes. His big hooks threw Riddle off his game. The second round was dead even with Martinez landing early in the round. The end of the round had the crowd roaring as the fighters teed off on each other.

Riddle finally got the fight where he wanted when he landed a third-round takedown. That's his comfort zone. Riddle briefly threatened by taking Martinez's back. Martinez avoided any serious trouble and got back to his feet before Riddle landed another takedown. This was Riddle's best moment of the fight. Trapped along the cage, Martinez ate some big shots.

"I had fun out there. It was a great fight and Matt is a tough guy. Even if you go in with the best plan in the world and study your opponent, they can change it up on you. We pushed each other hard but had a great time," said Martinez

You can watch UFC 143 right here on Yahoo! Sports