Nik Lentz used Fight of the Night bonus money to pay for father's life-saving surgery (Yahoo! Sports)

The telephone rang on Christmas Eve, as Nik Lentz was headed to a friend's home for a holiday party. He saw the phone number of his manager, Monte Cox, appear on his caller ID.

Lentz, a UFC fighter, wasn't expecting to hear from Cox. When he saw who it was, he briefly wondered why he'd be getting a call from Cox on Christmas Eve.

Perhaps, he thought, Cox was calling with holiday wishes. Or, he surmised, Cox had a fight offer to present that might have been good news.

Lentz answered and Cox's familiar voice came on the line.

But this was not a pleasant call, definitely one that Cox did not want to make.

Cox told Lentz he'd been talking to UFC officials, and they weren't happy with Lentz's fighting.

Two weeks earlier, Lentz had lost a bout to Mark Bocek at UFC 140 in Toronto. About 14 months before that, Lentz defeated Andre Winner in a fight that UFC president Dana White didn't find too compelling.

White, as is his style, held back no punches. He blasted Lentz and Winner for putting on what he believed was a horrible fight. The fans picked up on it and began ripping Lentz. The level of hatred and animosity directed toward him was, he said, utterly shocking.

But nothing was as shocking as the news Cox was to deliver. After eight UFC fights, the UFC had seen enough.

On Christmas Eve, Nik Lentz lost his job.

Being unemployed did not make Lentz very happy. The party was not much fun. It was not, however, the most significant of his problems.

His father, Jon Lentz, had been the glue around which the family had been built. Jon had dreams of seeing his son succeed athletically, but also wanted to help his two daughters reach their dreams.

He put one daughter, Mandy Kopmick, through law school. His other daughter, Alyson Lentz, was planning to go to medical school at the University of Minnesota and Jon was going to finance that.

All three children pleaded with him to keep his money. They would, they said, find a way to take care of themselves.

Jon Lentz had cancer. First, he'd had non-Hodgkin's lymphoma, but he was able to beat that. But then, the cancer came back and it surfaced in his lung.

Miraculously, he beat that, as well. But then, a third time, the cancer found its way to Jon Lentz's bladder. And this time, it didn't look so good.

Doctors said there wasn't much they could do beyond a surgery that would cost Jon Lentz around $100,000.

"Family was a huge thing to my father, and he taught me that from a very young age," Nik Lentz said. "If you don't have family, you don't have anything. He'd said throughout my whole life and throughout my sisters' lives that he'd be there for us. He'd say, 'I am going to do everything in my power to put you in a situation to be successful.' He was going to take care of his family. That was very important to him."

So, perhaps it wasn't too surprising, knowing that about Jon Lentz, to know that when decision time came, there really wasn't much of a decision.

Jon Lentz declined the surgery he needed to save his life, because if he paid for it, he couldn't afford to pay for law school and medical school and to put his children in the best possible position to be successful in their lives.

Jon Lentz is a former musician and studio engineer. He's 49 now, not all that comfortable talking about himself, even less about his private medical issues.

"I'm doing pretty good," he says.

He's recovering from a heart attack, his most recent malady, and he's not strong enough to travel to be in his son's corner.

"The thing that makes me the angriest about all this is that Nik's last three fights, I haven't been able to be there," Jon Lentz said. "That's been the hardest part. I never missed one of Nik's wrestling matches. Never. I never missed a fight. I was there all the way through. It's just been these last three fights, I haven't been well enough to go."

At Christmas 2011, there was a good chance Jon Lentz would never see his son fight again. First, Nik was out of a job and second, Jon had a life-threatening form of cancer.

Nik kept the bad news about losing his job to himself until after Christmas. 

"Everything that was going on, why ruin things for them?" Nik Lentz asked. 

He delivered the news shortly after Christmas. Jon Lentz, who was accustomed to seeing his son have so much success, was floored.

He believed his son was headed for big things as a fighter. 

"You talk about something tough to take," Jon Lentz said. "He had a pretty good record. He was doing well. And they cut him. I couldn't understand it."

Neither could Nik. He talked to Cox and asked Cox if he could make a call to UFC matchmaker Joe Silva to plead his case.

"When they've made up their minds like this, there's no changing it," Cox told Nik Lentz.

When his father became ill, it was Nik's turn to take care of the family. That's what the Lentzes did: They looked out for and took care of each other.

But now, here was Nik, the oldest child, the de facto head of the family with Jon battling for his life, without a job and unable to carry the family Jon had so nobly put on his shoulders.

All of the breaks were going against Lentz when, finally, one finally went his way. 

Paul Sass was set to fight Evan Dunham at UFC on Fox 2 on Jan. 28, 2012, in Chicago. However, Sass was injured in training and Silva, with no one else available to fight Dunham, called Cox to ask if Lentz would take the bout.

The paperwork to process his cut had not been filed; that was not unusual, because it often took a few days, even up to a couple of weeks, for all of the paperwork to be filed and for everything to be legally compete.

So, even though Lentz had been told he was cut, he was actually still on the roster. The UFC needed him and Lentz said, "Of course."

And that was the day his life changed dramatically.

Lentz hadn't been training – "I'd been pouting," he said – and wasn't in great shape when Cox called. But he never had any hesitation.

And when he fought, he fought with a fury, and a passion, that he had rarely shown before. The Lentz who was chastised by White and savaged by fans was suddenly in a fierce brawl with Dunham.

The doctor stopped the fight in Dunham's favor at the end of the second round because Lentz suffered a large cut just below his right eye and couldn't safely continue.

It didn't matter. The crowd loved the fight, and so, too, did White and Silva.

Lentz won a $65,000 bonus for Fight of the Night.

Many UFC fighters have purchased fancy sports cars, or new homes, or jewelry, with their Fight of the Night bonuses.

Lentz, though, never had a doubt about what he'd do with his bonus.

"I took that $65,000 and I didn't pay my manager's fees or anything else and I called my Dad and said, 'Now, you're having that surgery,' " Nik Lentz said.

"I knew that was the only thing I could do with it. I've been poor lots of time in my life. I can live without money. But my Dad and I were so close; we were such a close family. I didn't know if I could live without my Dad. It was an easy choice."

Jon Lentz tried to resist, but there was no telling his son no. The son was going to give his father that money and arrange for the life-saving surgery.

It was no different, Jon came to realize, than when the kids were asking him to spend his money on his surgery and he was saying no, that he had to pay for law school, and medical school, and so many other things.

Now, the roles had shifted.

"I don't have the words to tell you what that meant to me that Nik would do that," Jon Lentz said. "It was probably the most special thing ever to happen to me."

After the loss to Dunham, Silva could have cut Lentz again. But he recognized what Lentz had done for him. He walked over to Lentz in the cage after the bout and told him he would get a contract extension.

Something inside of Lentz changed. Before, he'd been a massive lightweight, a guy who cut down from 186 pounds to make the 155-pound division limit.

He bugged Mike Dolce, the noted MMA strength and conditioning guru, for help. Dolce agreed, on the condition that Lentz drop to featherweight. Lentz was skeptical but, as he was soon to learn, Dolce knows his stuff.

Lentz weighed less, but he was faster, stronger and more explosive as a featherweight than he'd ever been as a lightweight. He moved to Coconut Creek, Fla., to join American Top Team.

With a new team in place, he's won three in a row in the UFC and became the first American ever to twice beat a Brazilian on Brazilian soil.

He's moving up in the rankings and looking forward to bigger and more significant bouts.

And Jon Lentz has one vision left, too.

"I always believed that Nik had that special ability," Jon Lentz said. "I know the day will come when Nik wins that UFC [belt]. I know that will happen. He knows it, too. And I'll tell you what: When he gets there, that is a fight I am not going to miss."