Nate Campbell was 36 years old and supposedly setting out for one last payday before retirement when he shocked the boxing world by claiming the unified world lightweight title in March 2008.

Campbell's convincing points win over the previously unbeaten and highly-touted Juan Diaz sent the IBF, WBA and WBO 135lbs belts his way and turned him overnight into a man in demand.

It was a spectacular career resurrection for Campbell, who had only turned professional at the age of 28 and seemed likely to have to settle for a career on the fringes of the world's elite.

A defeat to Joel Casamayor in 2003, followed by two stoppage losses to Robbie Peden in March 2004 and again one year later, had seemingly left the Jacksonville, Florida fighter with nowhere to go.

But a series of wins at the end of 2007 lifted Campbell back up the IBF's rankings and into a mandatory position which appealed to the handlers of Diaz, who believed they were on the cusp of much greater fights.

In the wake of his stellar points win, Campbell courted the world's press and expressed his willingness to head straight into a title defence against the then unbeaten former Olympian Amir Khan.

Instead, just when the fame and fortune finally seemed to be heading his way, Campbell would find himself plunged into one of the most troubling and frustrating periods in his career.

Sixteen months after his win over Diaz, Campbell heads into his WBO light-welterweight title challenge to Timothy Bradley in Rancho Mirage, California on Saturday night with plenty to prove.

"I was the oldest man ever to win the world lightweight title for the first time," said Campbell. "I thought I would be embraced by the boxing community and loved by the people that I had fought so hard to entertain.

"Instead I was marginalised. All that has done is make me one vicious, angry and nasty fighter."

Campbell's problems started on the night of a scheduled first defence against Dominican Joan Guzman. When Guzman failed to hit the 135lbs limit, he pulled out of the fight.

The decision irked Campbell, who had expressed his willingness still to take on Guzman without his titles on the line, a decision he believed Guzman's handlers had accepted.

"I don't want to make it sound bad but aren't we sick of these guys that are so self-absorbed that they don't do the job that's there for them to do?" said a dejected Campbell on the night. "All he had to do was make the weight."

Campbell's words would come back to haunt him. When his first defence was finally arranged, against Ali Funeka in front of his home-state fans in February this year, it was Campbell's turn to fail to make the weight.

Campbell said: "At the age of 37 my body decided it wasn't going back to 135lbs. I sat in a sauna for nine and a half hours trying to make the weight. I missed it by two and a half pounds.

"It was a crushing thing in my life, but me being the fighter I am, I fought. I owed to Funeka to allow him to try to win my title."

Campbell won, but lost his titles. Now he is moving up to challenge Bradley at 140lbs, eager to win back a world title belt and belatedly relish some of the fruits of success that he feels were denied him.

"I didn't get the enjoyment of being a world champion. I don't know why everybody kept saying I was on top of the world because I made no money from it. I should have been kicking the doors down," he said.

"I sat there and watched Juan Diaz go on and make about US dollars 10million after he'd lost to me. How does that happen? It made me a lot nastier as a person. There's a part of me now that has this silent anger I keep within myself."

"Watching Tim's last fight I can tell he doesn't have a strong chin. Every time (Kendall) Holt threw a punch Tim went down. It's one thing to talk trash and another thing to be able to back it up in your home town."

Campbell's challenge to Bradley is one of the most intriguing fights of the year.

Undefeated Bradley dethroned Junior Witter in May last year and subsequently made two title defences against Edner Cherry and Holt.

Adding intrigue to an already strong card, Witter features on the undercard in another excellent-looking fight against top American prospect Devon Alexander in a battle for the vacant WBC crown.

For Bradley, fighting 10 miles from the place he was born, Saturday night will be all about an overdue homecoming.

He said: "This is my city, the place I was born, and I'm proud and happy to be able to perform in front of my home-town crowd."

For Campbell, it is about overdue respect and glory.

Finally, if he can pull off victory over Bradley in a fight likely to be decided on tight scorecards, he might just start getting the plaudits he deserves.