Heavyweight Steve Cunningham is a two-time cruiserweight titleholder and has boxed in eight world-title bouts. But his next fight will be the biggest of his career.

He takes on 2008 Ukrainian Olympic bronze medalist Vyacheslav "Czar" Glazkov (19-0-1, 12 KOs) in a title elimination bout that will secure the winner a mandatory shot at the biggest prize in boxing, the heavyweight championship against the winner of the April 25 fight between champion Wladimir Klitschko and Bryant Jennings.

Glazkov-Cunningham Where: Bell Centre in Montreal, Canada

When: Saturday, 9:45 p.m. ET/PT

TV: HBO

Cunningham (28-6, 13 KOs), of Philadelphia, and Glazkov meet in the co-feature of unified light heavyweight titleholder Sergey Kovalev (26-0-1, 23 KOs) making his fifth defense by facing former champion Jean Pascal (29-2-1, 17 KOs) on Saturday night at the Bell Centre in Montreal (HBO, 9:45 ET/PT), Pascal's hometown.

"The stakes for this fight are the ultimate stakes," Cunningham said. "This is the fight to get to the heavyweight title. This is that fight that gets you there. Every fight I have had has been the most important fight of my career, but this fight is on the stage for that No. 1 spot. This is to get to the champion. This is the biggest fight of my career. This is the biggest fight of a lot of peoples' careers.

"I want to capitalize on it. I want to make the best of it. I want to get in there and do what I am supposed to do. I want to get in there and do what I know I can do. I don't want to be concerned with Glazkov. I am just focusing on me. This is the upper-echelon stakes."

Cunningham is 38 and will be fighting on HBO for the first time in his 15-year career. That just adds to what is at stake.

"I am excited. This is my first time in Canada. From the Pascal fights I have seen, the fans in Montreal are crazy for boxing," said Cunningham, a U.S. Navy veteran and a small heavyweight at 209 pounds. "I am happy to finally be here."

The 30-year-old Glazkov, who is 218 pounds, scored his biggest win against former cruiserweight champion and longtime heavyweight contender Tomasz Adamek last March but also has a dubious draw with Malik Scott, whom many believe beat Glazkov.

"I ain't worried about none of that," Cunningham said. "I need to do what Steve Cunningham does. I come to kick butt. I come to win. I come to walk out of there with my hands raised. I just need to get in there and handle this business.

"I have been the underdog since I started boxing. The main thing to do is keep the faith. When you believe in what you are doing, you love what you do, and [if] you work hard at what you do then nobody can stop you. I have always been the underdog, always. I was the underdog for so long, so that motivation is just built into me."

Although Glazkov is a formidable opponent, Cunningham can't help but think about what it would be like to face Klitschko, a much bigger man and a dominant champion.

"A lot of fans want to see you take the throne from the king. I am a boxing fan myself. Before I was a fighter I was a fan," he said. "I understand the fans want you to take the crown from the king. I would love to fight Wladimir because when you are a champion and you are at that level, the challenges are what drive you. It is not just money. A champion wants to put himself up against the best.

"He wants to see how he fares against the best. Wladimir Klitschko is the best right now. I would love to challenge him. I have been to camp with Wladimir twice. He and I have a good relationship. We talk all the time. We've got the same lawyer. I totally respect him."

Besides being motivated by knowing that a win will get him a heavyweight title shot, Cunningham is also motivated by his 9-year-old daughter, Kennedy, who underwent a heart transplant in December after living her whole life with a life-threatening heart condition.

"We have been dealing with this situation for nine years," he said. "It has just been the last year and a half that the boxing world has really heard about this. I have fought all over the world while I have been dealing with this. This is my life. I have been a two-time world champion with this in my life. I use it as energy. I use it as fuel and I press on. There's a job that I must do.

"I have three children, not just Kennedy, so I have to provide for my entire family. I can't just shut down. I have two sons and a nephew that I have to take care of. I got a job to do and a family to take care of. During this whole ordeal I have seen her face things that would make grown men shake in their bones, but she takes them on with a smug smirk on her face and says, 'Let's go!' I do remember that look on her face going down to the transplant, and I have visited that look in my memory when times have gotten hard in training camp. If she can go in there and get a transplant with that much heart, then me going into these fights is nothing."