Amir Khan and Marcos Maidana got a close-up look at one another at a news conference Tuesday to promote their Dec. 11 fight in Las Vegas. Photo / Tom Hogan-Hoganphotos-Golden Boy Promotions

LOS ANGELES – Amir Khan couldn’t have imagined it at the time but he said his first-round knockout loss to Breidis Prescott in 2008 was the best thing that could’ve happened to him.

Had he beaten Prescott, he probably would’ve remained in England — with his old trainers and his old habits — rather than go to the United States to work with trainer Freddie Roach and fitness coach Alex Ariza.

The gifted former Olympian probably would’ve been a fine fighter but possibly not the force into which he seems to be evolving under Roach.

“If that didn’t happen, I don’t think I’d be in this position ÔǪ in a big fight as a world champion,” said Khan, speaking at a news conference to promote his fight against Marcos Maidana on Dec. 11 in Las Vegas.

“Things happen for a reason. I want to thank Prescott for that.”

Khan (23-1, 17 knockouts) has been dismissed by some as having a weak chin, the result of a perfect left hook from which he never recovered.

Prescott put his semi-conscious prey down two times, the second time for good in one of the more-stunning upsets in recent years given Khan’s pedigree.

Khan accepts the setback as a learning experience but rejects the notion that he can’t take a punch.

“Definitely not,” he said. “ÔǪ I’m sparring with guys who weigh 154 pounds and no one has ever touched me. The only time I had problems was when I was killing myself to make 135 pounds. When you kill yourself to make weight, it does make you quite vulnerable. When I spar at my natural weight, which is 145 pounds walking around, I’m OK. No one can touch me. You can ask Freddie. I sparred with Manny. He hit me with his best shot and didn’t drop me. He didn’t even wobble me. And that’s Manny Pacquiao, one of the best fighters pound-for-pound in the world and one of the biggest punchers in his division.

“Let [people] think that. If Marcos Maidana thinks that, he has a shock coming on Dec. 11. When he hits me with everything he has and I’m still there in front of him, we’ll see how much heart he has left.”

The loss and the perception of his vulnerability is a small price to pay for his status today.

Khan, now 23, left England behind shortly after the Prescott fight and joined Roach at the Wild Card Boxing Club in Hollywood, Calif., where Khan believed he’d get a fresh start with one of the best trainers in the world.

Roach loved what he saw from the beginning, insisting that Khan had rare gifts and would become a star with some molding and strict fitness training.

It’s hard to argue with the results. Khan is 5-0 (3 KOs) since he started working with Roach, including victories over Marco Antonio Barrera, Andreas Kotelnik and Paulie Malignaggi.

The KO loss, he said, “made me a better all-around fighter ÔǪ and more focused and more disciplined.”

“If I would’ve won that fight,” he said, “I would’ve stayed in the UK and done the same old thing ÔǪ eating burgers and chips and all that stuff. I probably would be getting bigger and bigger in size, not being as focused as I am now. All the distractions in England, I left them there.

“I train hard. I eat, sleep and drink boxing now. That’s all I do.”

Maidana confident: One of the most-intriguing elements of this fight is the perception of Khan’s chin coupled with Maidana’s unquestioned power, which ranks among the best in boxing pound-for-pound.

What will happen when Maidana’s fist connects with Khan’s chin?

Maidana (29-1, 27 KOs) doesn’t know. He said he isn’t one of those who is convinced that Khan has a weak chin, although he is certain that he will test it at some point.

The tough Argentine speaks with the confidence of a fighter who has stopped all but three of his 30 opponents, including Victor Ortiz in June of last year.

“I’m not sure 100 percent about that,” he said of Khan’s chin, speaking through a translator. “He was hit very, very hard with a lot of accuracy by Prescott. I can’t really tell. ÔǪ And he has a lot of speed; it’s not easy to him hard like Prescott did. All I can say is that I’m preparing myself to try to catch him.

“And I know through 12 rounds that I will sooner or later have an opportunity to catch him and hit him.”

Maidana is convinced that his opponents generally won’t the make the mistake that Ortiz made, standing toe to toe with him. His punching power is not a well-kept secret.

That includes Khan, who he expects to move the entire fight.

“I think I will have to work very hard to catch him,” Maidana said. “I picture the fight with him running all the time and being very defensive and counter attacking, of course. So I’ll have to chase him from Round 1 on.

“ÔǪ People know about my punching power. It would be stupid for them to stand in front of me.”

Khan might surprise Maidana.

The Briton said he has no intention of moving his way to a decision victory. He wants not only to win but also give the fans something to remember when he does.

“You might see me being the pressure fighter and Maidana the fighter going backward,” he said.

Khan’s plans: Khan said he doesn’t plan to leave the deep 140-division anytime soon even though he undoubtedly will move up in weight because of his height (5-10; 178cm).

He said he struggled to make 135 but 140 isn’t difficult. He weighed 149 at the news conference, his normal walking-around weight.

Ariza has helped him become more disciplined in terms of his fitness training and better distribute the weight on his body.

“I make weight quite easy,” he said. “You can see how much weight I had to lose to make 135. I was a lot bigger then, as well. I did a lot of weight training and stuff. I was very, very top heavy. ÔǪ I killed myself making 135; 140 is reasonable. Those last five pounds used to kill me.

“I’m more professional now. I cut down on the size at the top, built up my legs a little more, changed a lot of stuff.”

Thus, he feels confident that he can clean out the junior welterweight division if he can continue to get big fights.

He said he would love to take on the winner of the tentative Timothy Bradley-Devon Alexander fight on Jan. 29 if he beats Maidana at the Mandalay Bay Resort & Casino.

“I think that fight should happen, the fight people want to see,” he said. “I want to clean up the division properly, fight the best in the division. ÔǪ If I want to be known as a great fighter, to have a good boxing legacy, then that’s what I have to do.”

One worder: The promotion has been labeled “Lightning and Thunder.”

Maidana was asked which one applied to him. His response: “Both.”