Junior dos Santos' nice-guy persona is no act as he prepares for Alistair Overeem

LAS VEGAS – Fighters at news conferences often turn into actors. They know full well that threats of violence and vows of imminent harm about to befall an opponent grab attention and help sell tickets.

Junior dos Santos, the UFC heavyweight champion and one of the foremost knockout artists in mixed martial arts, knows that as well as anyone.

He'll defend his title against former Strikeforce and K1 champion Alistair Overeem, also a big-time knockout king, in the main event at UFC 146 on May 26 at the MGM Grand Garden.

At a kickoff news conference in the lobby of the hotel on Tuesday, Dos Santos tried to deliver the predictable, ticket-selling line.

"He has good stand-up skills," dos Santos said of Overeem. "He's a striker. I'm a striker."

He was on a roll. He seemed dead serious. He wasn't snarling and snorting and he didn't channel his inner Mike Tyson and threaten to eat Overeem's kids, but he was doing the expected.

But, as dos Santos began to deliver the clincher, he couldn't help himself.

"Somebody," he said, trying to suppress a giggle, "is going to get knocked out."

That was about as good as a promoter could hope to get from dos Santos, who's about as easy-going a guy as one could hope to find in combat sports.

He's as friendly and accessible as any major athlete that exists in sports. On Wednesday in Los Angeles, he was caught on the streets by a TMZ cameraman.

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Normally, that's not good news for UFC president Dana White, who has had to see TMZ report on stories such as Quinton "Rampage" Jackson's erratic driving on an Orange County freeway and Tito Ortiz's arrest after an issue at home with girlfriend Jenna Jameson.

White, though, doesn't need to worry about dos Santos, who threw his arm around a TMZ cameraman and began singing songs from Adele and Katy Perry. This came after he spent an afternoon doing interviews at the Yahoo! Sports studios in Santa Monica, Calif., and burst out singing there.

"He has a genuine good-hearted nature that resonates with fans, fellow athletes and the media," said Dave Sholler, the UFC's director of communications who escorted Dos Santos on his media tour of Los Angeles. "He's a really funny, light-hearted guy. A lot of media who are new to MMA see him as this 6-foot-4, 240-pound giant of a man. But when you sit and talk with him, what they find is that he's really just a 28-year-old kid who loves music, good steakhouses and really loves to have a good time."

Sholler said dos Santos drove him to the airport. As the two were riding, dos Santos was belting out Metallica's "Enter Sandman." He pointed out that it was once ex-champion Brock Lesnar's ring walk music.

He's been enormously respectful of Overeem and raved about Overeem's myriad accomplishments.

"When you see what he has done, you just go, 'Wow!' " dos Santos said. "It's impressive."

The nice-guy routine – it's no act – works only when one wins, though. There are plenty of nice guys in the world, but not many of them are able to knock out the fittest, best-conditioned big men in the world with a single punch.

For dos Santos to become a star in the U.S. as well known as Chuck Liddell, who is probably the biggest star to have ever competed in the UFC, he's going to have to continue his winning ways.

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Overeem presents him with a huge challenge, figuratively and literally. Overeem has several inches and probably 25 pounds on Dos Santos. More significantly, Overeem's striking is more diverse than anyone Dos Santos has met, and Overeem's knees will undoubtedly be a factor when they fight at close range.

But he's put in the time to diversify his game so he's not just a one-trick wonder.

"I love boxing, and I'm a really confident guy in my hands," he said, explaining why he's now spending more of his time working on wrestling, jiu-jitsu and Muay Thai than boxing. "I really believe I can knock anyone out."

As he spoke about the fact that he expects his fight to end in a knockout considering the power of the two men in the bout, he again chuckled.

After saying he expected a knockout, he beamed and said, "Or, you guys will see a striker trying takedowns."

He leaned back in his chair and smiled broadly.

That's the essence of Junior dos Santos, the smiling assassin. He's equally comfortable belting out the latest Katy Perry hit on the streets of Los Angeles as he is mowing down the best heavyweight fighters in the world.

You don't have to be mean to be good. No one makes that point better than Dos Santos.

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