Kimbo Slice does just enough to get past Houston Alexander

Reporting from Las Vegas — 

The celebrity of Kimbo Slice has performed incredibly for the Ultimate Fighting Championship. His cardio fitness is another story.

Slice, costarring in a bout filled with an abundance of lulls in his UFC debut before a paying audience, landed enough big punches and inflicted enough damage while atop light-heavyweight foe Houston Alexander to win a unanimous decision.

“It’s work, it’s not easy,” Slice told the crowd, which had often booed the inactive lapses at the Palms hotel. “I would have preferred to knock him out. I had to call him out, I reverted back to the streets.

“I couldn’t rush in there. I would’ve got knocked out. I think that shows my maturity as a fighter.”

Slice, the YouTube phenomenon whose street fights made him a main-event fighter in a now-defunct mixed martial arts operation, came to the UFC as a contestant on the reality television series “The Ultimate Fighter” on Spike TV.

He was eliminated in the first round by Roy Nelson, but Spike reported massive interest in the popular series, with an average audience of 3.5 million viewers compared with the typical average of 2 million in its nine prior seasons.

Nelson became champion of “The Ultimate Fighter” on Saturday, winning a six-figure UFC contract by unleashing a wicked right that knocked out Brendan Schaub, Nelson adding another right to the head as the fight was stopped at the 3:45 mark of the first round.

Wisely, UFC will keep Slice around too, hoping he’ll produce a breakout performance that will give credibility to his imposing character.

Saturday wasn’t it.

Slice and Alexander spent the first three minutes of their light-heavyweight bout mocking “Dancing With the Stars,” before Slice finally charged and landed a couple of scoring rights. Alexander’s left leg kicks were not an issue.

In the second round, Slice scored three takedowns of Alexander (9-5), once barraging Alexander with hard rights to the head that set up a submission choke attempt that failed.

Slice started the third by getting the best of a standup exchange, but the action lagged again and it was clear Slice was fatigued. Alexander hit Slice with lefts, and Slice missed a wild left punch. A leg kick by Alexander then sent Slice to the canvas.

In the final minute, neither of the two men showed the energy to fully engage, and the best punch was an Alexander right that backed up Slice.

Slice will have another chance to impress, but the best words for that fight was what a Spike official said while passing press row: “Ratings gold.”

Saturday’s card also featured one of the UFC’s most dynamic athletes, unbeaten light-heavyweight Jon Jones.

Jones started brilliantly against Matt Hamill, knocking him down and inflicting windup punches and elbows. Toward the end of the assault, Jones delivered illegal elbow blows to Hamill’s head and the referee stopped the fight to deduct a point from Jones. Hamill couldn’t continue. Hamill was declared the winner by disqualification.

In other action, a fight between “The Ultimate Fighter” semifinalists and ex-NFL players Matt Mitrione and Marcus Jones ended 10 seconds into the second round when Mitrione dropped Jones with a straight right, bringing a technical knockout stoppage.

lance.pugmire@latimes.com