LONDON, England — Dave Allen exacted the most brutal revenge possible over Johnny Fisher as he produced a frontrunner for the Knockout of the Year at Copper Box Arena.

The pair had shared 10 rounds at the Kingdom Arena in Riyadh, Saudi Arabia, in December, with Fisher climbing off the canvas to clinch a controversial split-decision victory.

Allen did not complain once about the decision, despite many others arguing in his favour, but he was given the chance to put the record straight as Fisher, to his credit, took the immediate rematch.

But, 147 days later and back on home soil, Allen was leaving nothing to chance. He had tried his luck with his trademark overhand right early on with little success as Fisher opted to box long.

Then, in the fifth, the 33-year-old from Doncaster took his chance in chilling fashion, dropping Fisher with less than 30 seconds left of the round. It was the same round that Fisher had gone down in Riyadh but this time Allen would not let him off the hook.

Moments before the bell sounded to end the round, Allen found the target with a slashing left hook and followed it up with a right uppercut. All 6ft 4in of the Romford Bull fell face first to the canvas as the towel flew in.

Allen said: “I put the extra weight on because I thought it would help me knock him out. I took that risk and it paid off.

"The first fight done me the world of good. I put a bit of weight on for the body shots. Took the risk and got [the title].

"My kids can have an en suite now, that's the dream. At this level, I'm a handful. This means everything to me. I've been written off so many times. I am the fattest, hardest man you'll ever see."

The previously undefeated Essex man had come straight out behind a long and high guard, in a clear attempt to keep his shorter opponent at long range. Allen did not seem in much of a hurry to close the gap but he did attempt to land the long, arcing overhand right, which has been a honey punch of his over the years, three times in the opening round.

Fisher had nearly found a home for his right hand in the closing seconds of the first and he just started to find his range during the second. A few hard jabs pierced Allen’s guard and one big right hand drew cheers from his vociferous following.

Still Allen attempted to land with that right hand. The self-styled "Doncaster De La Hoya" had weighed in 7lbs heavier for this rematch than he was for the first fight and had suggested that he had done so in a bid to force an early finish. But it was clear early on, that would not be a finish built upon industry but rather one well-timed haymaker.

Meanwhile, Fisher continued to box intelligently behind a long jab, only occasionally choosing to attempt anything more menacing. But as the third round entered its final minute, Fisher landed with two short uppercuts when up close. However Fisher did receive a telling off from referee Marcus McDonnell after landing a left hook after he had called break.

Allen came within a whisker of finding the target with that right hand with a minute left of the fourth but it was otherwise a good round for Fisher, who was jabbing hard to head and body. He closed another solid three minutes’ work with a solid right hand down the pipe.

But that was as good as it got for Fisher, who was knocked out in brutal fashion in the very next round. Allen had landed with that right hand and a left hook after 60 seconds of the fifth and Fisher visibly retreated as a result.

Another right hand then seemed to stiffen Fisher’s legs as things went from bad to worse for him. Fisher was down with 23 seconds left in the round after a right hand, left hook but he managed to clamber up in time to beat McDonnell’s count.

He seemed on unsteady legs as he was allowed to box on and Allen took full advantage. The left hook switched his lights off and the right uppercut sent him face first to the canvas.

Promoter Eddie Hearn revealed afterwards that there is a rematch clause, with the heavyweights now locked at 1-1, but admitted that it one for "down the line." At one point, Allen’s career looked dead and buried but now he can look forward to a headline fight in Sheffield.