Maybe it is about the size of the dog in the fight after all.

Well, a dog really isn’t the right animal noun to describe Brock Lesnar. Beast would be a more appropriate description for the 6-foot-3, 275-pound behemoth.

Despite having just three mixed martial arts bouts under his belt before Saturday night’s title fight at the MGM Grand Garden Arena, Lesnar dominated former Ultimate Fighting Championship heavyweight champ Randy Couture.

When Lesnar — who was a full 50 pounds larger than Couture — didn’t dwarf the UFC legend with his sheer body mass, the former World Wrestling Entertainment champ dismantled the 45-year-old with his speed, strength, and of course, size.

“They are some big-ass ham hocks coming at you,” said Couture, after losing his title via a second-round TKO at the hands of Lesnar’s specialty-made XXXXL-gloves.

“I felt good. He’s just a big guy. He caught me with a big shot,” continued Couture, who thought he side-stepped Lesnar’s big right hook, but instead crumpled to the mat where he was greeted with at least two dozen more finishing blows.

“I must have hit him I think about 40 times and I was wondering, ‘Is this referee ever going to come in here and stop this?’ ” said Lesnar, after stunning the near sellout crowd of 14,272.

For a split second Couture looked as if he might somehow survive the flurry of leather bouncing his head off the canvas. But referee Mario Yamasaki stepped in and signaled the stoppage at 3:07 in the second round.

“I can't believe it’s like a dream right now, so it’s pretty awesome.” said Lesnar after claiming the championship belt, which White joked, ‘We’ll have to find a larger belt.’”

The title marks the third such honor that Lesnar has achieved in his fighting career. But he admitted that the WWE championship, nor even his 2000 NCAA heavyweight wrestling title at Minnesota could compare to hosting the UFC championship.

“I believe in hard work and that it pays off,” he said.

"I may come across as a cocky SOB, but I believe in myself. I've got the utmost respect for Randy Couture. He's been a great champion."

The league’s elder statesmen returned the compliments, warning media members that they were only watching the early stages of what he said will be a standout career for Lesnar.

“I was referring to, kind of having an idea where Brock is at in this stage of things. He’d love to go out and submit guys, it will probably take him a while to learn some more submission skills and feel really comfortable on his back,” said Couture, who was making his first fight in 15 months after a contract dispute with the UFC.

“I’m sure he would love to refine his striking, kicking and all those other things with that great big body. But it’s probably gonna be a while before that feels real comfortable for him too.

“I can remember those feelings of wanting to do those things and not feeling technically sufficient,” Couture continued. “Wrestlers have a particular mindset, they’re perfectionists. They break things down by the numbers, but it still takes time.”

That’s sounds fine to White, who said he was still in shock by Lesnar’s quick ascent to the top.

“To do what he’s done in his fourth fight, I’m still having trouble believing that,” said UFC president Dana White, whose self-proclaimed “biggest UFC fight ever” drew a $4.8 million gate Saturday — making it the fourth-largest in UFC history. Pay-per-view numbers will be calculated later this week.

“This is a different game than when Randy won the title without a lot of experience. These guys now, wow, they’re really great athletes and well-rounded.”

While Couture might not have much longer battling in the heavyweight class, he’s excited about the level of fighters that will soon carry the torch.

“It’s getting stronger and stronger,” Couture said. “Brock is a great indicator of where the heavyweight division is going. We’re seeing guys who aren’t just big guys, they’re also very, very good athletes.

Brock, obviously, is walking around with the title now, but more importantly, he’s on the right path to completing his game and adding all the skills to become a complete mixed martial artist. I know what that’s like. It’s fun, but you have to step out in that cage and prove it. And carrying that belt around makes you a target.

“There are a lot of great guys in the division now. ‘Napao’ Gonzaga looked good tonight and he looks like he’s heading in the right direction. There are a ton of guys.”

Couture’s not ready to take himself off that list yet either.

“I still feel like I'm getting better as a fighter so we'll see," said Couture (16-9), who has two fights left on his UFC contract.

“I'm going to let things settle down and see what happens. "I still feel like I'm getting better. I still enjoy fighting."

So too does Lesnar, who said he was uncertain of what exactly his next step would be after he faces the winner of the interim heavyweight title between Frank Mir and Antonio Rodrigo Nogueira, who meets Mir for that belt at UFC 92 at the MGM Grand on Dec. 27.

“I try to learn every day and I train hard every day,” Lesnar said. “I work with a good group of guys and we go and drill things, over and over. You have to be a well-rounded fighter in this day and age. I want to continue to mold myself into a dominating fighter.”