INGLEWOOD, Calif. — Chael Sonnen and Quinton Jackson agreed to a bet last month on a media tour. “Rampage” was so confident Sonnen would not be able to take him down, that he said he’d give Sonnen $10,000 for every takedown he landed at Bellator 192.

Well, it seems as if Jackson is going to be owing Sonnen some money.

Sonnen defeated “Rampage” by unanimous decision (29-28, 29-28, 29-28) in the main event Saturday night at The Forum. The victory sends Sonnen into the Bellator Heavyweight World Grand Prix tournament semifinals, where he’ll face the winner of an April fight between Fedor Emelianenko and Frank Mir.

Sonnen was able to take Jackson down in each round, which means “Rampage” technically owes him at least $30,000.

“We’ll see if he is a man of honor,” Sonnen said at the post-fight press conference. “We did shake on that. I’ll tell you on the other side, I will not cash his check. But I do expect him to hand me one. What I do with it is my business. But I will tell you, I will not cash that check.”

Just getting “Rampage” down was a victory, Sonnen said. Regardless of any wager. Jackson weighed in at 253 pounds Friday morning, while Sonnen was 222. Sonnen was giving up quite a bit in mass and strength.

“It did feel good to get him down,” Sonnen said. “I was trying to pass his guard. I had a hard time passing it. He was very strong. Went for a can opener, I tugged on that big neck of his, it didn’t budge an inch. He was really a powerful guy. I put two arms on one of his, I had it locked out, I couldn’t budge it. It was like an iron pipe. He was a strong guy.”

One of the biggest keys to the fight was not actually Sonnen’s world-class wrestling. It was his striking. Sonnen was able to land some punches on Jackson in the first round and used that to get inside and eventually go for takedowns. Sonnen said “Rampage” complimented him on his boxing afterward.

“I had dreams in 2000 of being an Olympian for boxing,” Sonnen said. “I never talk about it. I ended up pursuing wrestling, but I’ve been boxing. I think I box more than any of these guys have. I don’t know if any of them have competitively boxed. I’ve competitively boxed. It’s definitely Plan B for me, but I know how to box.”

Sonnen beat Jackson on Saturday, but his next opponent — either Mir or Emelianenko — will be a true heavyweight. “The Bad Guy” said there are improvements he needs to make in order to be ready for that kind of task.

“I’ve gotta get better, for sure,” Sonnen said. “I’ve gotta make some changes. I didn’t fully know what I was getting into tonight.”

But he came out on top anyway.

Sonnen, 40, will roll on with a chance at the end of all of this to become the Bellator heavyweight champion. Not bad for a career middleweight.

“I felt like it was a really hard fight,” Sonnen said. “I felt like finding that range was really important, because I stepped in it a couple times. I got too close and he hit really hard. Whether you could see it or not, I’ll tell you, he hit really hard.”