Nathan Cleverly made a successful first defence of his WBO light-heavyweight title with a fourth-round stoppage over Aleksy Kuziemski at London's O2 Arena.
In an action-packed fight Cleverly appeared to break Kuziemski's nose in the second round before opening up a fresh cut midway through the fourth.
With blood splattered all over the challenger's face the referee decided the Pole was in no state to continue.
Welshman Cleverly is now unbeaten in 22 fights following Saturday's victory.
The Cefn Forest fighter was installed as the WBO world champion on Thursday after title holder Juergen Braehmer withdrew from Saturday's fight because of injury.
He was stripped of his title and Cleverly, the interim champion, was awarded the belt by default.
Braehmer was then replaced by Tony Bellew on Thursday but he later failed a check weigh-in after an eventful press conference with the pair trading insults.
Kuziemski then became the third change of opponent for Cleverly with the Polish fighter ranked at number 11 by the WBO.
But despite the rollercoaster week, Cleverly vowed to remain focused for the fight.
However, Cleverly was unusually erratic and wild in an eventful four rounds with the Welshman also rocked in the third.
Two stiff jabs from Cleverly found the target early on and his 34-year-old opponent realised very quickly that he was in for a difficult evening.
A right uppercut and a left hook followed by a short, sharp left seemed to hurt the challenger further before a solid right to the body also made the Polish fighter wince just before the bell.
Cleverly continued to work the body early in the second, his hand speed and power proving too much for Kuziemski who responded with two right hands over the top.
But the round was all one way traffic with Cleverly getting through at will while also seeming to break the challenger's nose with several powerful blows that smashed through the defence of Kuziemski who staggered to his stool at the end of the round with blood splattered all over his face.
To his credit Kuziemski tried to make a fight of it rocking Cleverly with a huge left-hook counter and, later, a left-right combination that wobbled the Welshman.
The fight was stopped in the fourth round
Cleverly dropped his hands and chose to trade with his opponent making the fight harder than it needed to be before he regained his composure and started to box behind his jab ending the the round on top
The doctor was called in to take a look at the nose of Kuziemski at the end of the third with the Polish fighter apparently told he would be given one more round to win the fight.
As a result he came out swinging but Cleverly was wise to the attack and the Welshman unleashed several smart shots that seemed to break the spirit and defence of Kuziemski as well as open up a new cut above his left eye.
That was enough for the referee to end the fight when he should possibly have consulted the ringside doctor as Cleverly earned his 11th stoppage in anti-climatic fashion.
Cleverly hailed his victory as the fulfilment of a lifelong ambition.
"I felt it was my destiny tonight," he told BBC Radio 5 live.
"Ever since I first put the gloves on when I was 11 this was the night I've been dreaming of.
"Now I'll say Nathan Cleverly is the light-heavyweight champion of the world."
Speaking about the theatrical build-up to the fight, he added: "What a rollercoaster week it has been, but I picked myself up and stayed mentally focused.
"I was happy with that, I'm going home a world champion."
Sections of the O2 crowd booed after they believed the fight was prematurely stopped with Kuziemski bleeding heavily, but Cleverly was confident he was moments away from victory in any case.
"I thought if the ref had kept it going on a little bit longer I would have put him on the canvas," he added.
"But the ref stepped in. That doesn't matter to me now. This is a great feeling."
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