Matt Skelton stopped last-minute stand-in opponent Mark Krence to retain his British heavyweight title after seven rounds of their fight in Bolton.
Chesterfield butcher Krence was only called in on the morning of the fight to replace flu victim Danny Williams and put in a brave performance.
He caused the champion some problems although Skelton was always in control.
The fight ended when Krence was forced to withdraw with a rib injury suffered during the contest.
Afterwards Skelton heaped praise on Krence, saying: "Mark did brilliantly.
"I didn't really fight well. That is not to discredit Mark, but if you watch footage of your opponent you can get your mind set on how to fight him.
"That's why it was a bit of an untidy fight but I got the job done and am still British champion.
"I'm glad I won as I was disappointed when Danny pulled out.
"I've never ducked a fight and don't know why Danny didn't take the fight but I think it discredits boxing."
Krence was delighted with his performance and said: "That wasn't bad. If I'd had eight weeks notice it would have been different and the best is yet to come.
"I've been talking about dropping down to cruiserweight but now I know I can still handle the best heavyweights."
Michael Jennings claimed the vacant British welterweight title with a first-round knockout of Birmingham's Jimmy Vincent on the undercard.
Jennings wobbled Vincent with a right hand midway through the round, then completed the job moments before the bell with a swinging left.
The belt had been stripped from his Collyhurst stablemate David Barnes after Barnes' loss against Ghana's Joshua Okine last month.
Jennings has now won all 26 of his professional fights.
"I want to take things steady and have a couple of defences of the British title now before I start thinking about moving up," said the Chorley fighter.