It happened 38-years-ago when no less a pugilistic personage than Muhammad Ali was let off when he failed a drugs test on the eve of his penultimate contest against Larry Holmes. 

Not many people seem to know that.

But it is a fact. Ali had been given banned diuretics in a desperate attempt to shed some of the flab he had accumulated at the tail-end of career spanning two decades.

When this showed up in a test, the Commission agreed to let the contest with Holmes for the World Boxing Council (WBC) heavyweight title proceed on condition that Ali never fought in the state of Nevada again.

And of course he never did. The curtain came down on The Greatest's 61-fight career a year later in the unlikely setting of Nassau, capital of The Bahamas, where he lost a unanimous decision to local heavyweight Trevor Berbick.

Ali's failed test, though formally recorded by the Commission, was never widely publicised.  

But on the night of October 2, 1980, in a ring set in the Caesars Palace car park, those of us present in the 18,000 crowd were acutely aware that 38-year-old Ali was on his last legs and that something was acutely wrong with him.

His uncharacteristic disorientation obviously was not only caused by the relentless hammering he absorbed in every round before his cornerman Angelo Dundee mercifully called a halt at the end of the tenth.

It was the night an icon disintegrated before our eyes as Ali, a robotic shell of the sublime athlete of his heyday, suffered a savage beating that even Holmes seemed reluctant to administer towards the end, repeatedly beckoning to referee Richard Greene to end his erstwhile idol's agonising humiliation.

At ringside, even many of us in the media seats were yelling "stop it, stop it" amid counter cries from some in the Ali entourage fearful of losing their meal ticket.

It was left to Dundee to defy Ali's frantic cheerleaders and end things. "I am the chief second and I stop the fight," he bawled at the referee as a dull-eyed Ali slumped on his stool. It was too late to save Ali's career, but it probably saved his life.

How much the ingestion of those diuretics affected Ali's performance is impossible to determine. But clearly it did him no good.

There is no evidence that Ali had ever taken drugs before. Indeed, when asked some years earlier whether Ali had done so Dundee responded: "No, he only ever gets high on himself."

It was also revealed after the fight that Ali had been examined at the Mayo Clinic, and the results were shocking. He had admitted to tingling in his hands and slurring of his speech. With the conclusiveness of Ali's loss to Holmes, and his worrying medical condition, it seemed incredible that he fought again.

According to Ferdie Pacheco, Ali's former ring doctor, "all the people involved in this fight should've been arrested. This fight was an abomination, a crime".

Pacheco had quit Ali's camp, in 1977, after the punishing fight with Earnie Shavers which had left Ali passing blood for days afterwards.

The Nevada Commission would have done Ali a favour had they banned the contest instead of letting him off with a token slapped wrist, thus arguably putting cash before conscience.

It is quite possible that they will do so again when they consider Canelo's case on April 10. The fiery Mexican red-head claims he must have eaten meat contaminated with the muscle-building steroid clenbuterol.

As it happens Ali is not the only former world heavyweight champion whose doping indiscretion seems to have been overlooked in the passage of time.

Vitali Klitschko, now retired after his long reign as WBC heavyweight champion, has admitted to having used steroids earlier in his career.

He tested positive for a banned substance in 1996 while trying to recover from injury when still an amateur, and was thrown off the Ukrainian boxing team for the Atlanta 1996 Olympics.

Vitali had planned to box at super-heavyweight while his younger brother, Wladimir, was entered to compete at the 201 pound heavyweight limit.

Wladimir, who was struggling to make his weight, took over the super-heavyweight slot and went on to win the gold medal.

Meanwhile, we await with intrigue the appearance in the United Kingdom on Saturday (March 31) of another former champion boxer proven guilty of drugs offences.

Alexander Povetkin, who won Olympic super-heavyweight gold in the 2004 Athens Olympics, and has also held a version of the world pro crown, twice failed drugs tests and was given an indefinite ban last year by the WBC.

But this has been conveniently lifted after presumed pressure from Russia and and he meets Britain's David Price, the 2008 Beijing bronze medallist, on the undercard of the Anthony Joshua v Joseph Parker blockbuster unification clash in Cardiff.

It so happens that the 38-year-old Povetkin, whose manager Andrey Ryabinski is said to be a close friend of Vladimir Putin, is the first Russian athlete to compete here since the poisoning last month of the former double agent Sergei Skripal. 

So it will be interesting to gauge the hostility of his reception from the 80,000 crowd at the Principality Stadium. From Russia with glove, eh?  

Far more interest will be focussed on the headline attraction between the two undefeated heavyweight champions.

I may be in the minority but I believe  Joshua has a far harder fight on his hands than many, especially the bookies, think. One makes him 12-1 on, others 10-1.

Those are ridiculous odds. Samoan-born Kiwi Parker, at 26, is younger and as tactically proficient as the 28-year-old London 2012 Olympic champion and had as good - if not better- a chin. However, he has to be more ponderous in his leg movement.

Joshua has an advantage in height and reach but he also has flaws when under pressure; we have seen him caught by Dillian Whyte, Wladimir Klitschko and Carlos Takam who have all exposed a certain vulnerability.

But Parker is a young, able and live opponent who can take a whack.

It could be close - maybe even a draw.

Parker may not splosh Josh, but he can give him plenty of bother.