The two unbeaten, unblemished Brits do battle at long last for the British and Commonwealth heavyweight titles held by Dubois, plus the vacant European belt.

The much-awaited collision of might and muscle will be held, bizarrely, at the headquarters of the Church of England, Church House, next door to Westminster Abbey and in the shadow of Big Ben and the Houses of Parliament.

Church House was founded in 1887 to commemorate the Golden Jubilee of Queen Victoria. The building suffered a direct hit in the early part of World War One, but due to its exceptional construction only minimal damage was done. The Prime Minister of the day, Winston Churchill, was so impressed by this that it was refurbished for use by the two Houses of Parliament for the remainder of the war.

Now it is the administrative hub of the Church of England, home of the General Synod and Archbishops' Council. It occupies the southern half of Dean’s Yard and sometimes serves as a convention centre but never before has it staged a boxing promotion. Or anything like it.

Not that the general public can take a pew - and Church House can seat 10,000 - on Saturday because of the coronavirus restrictions, but BT Sport cameras will show on their sports channel what even rival Sky’s head of boxing Adam Smith hailed as a "mouth-watering match-up" in a unique live telecast.

Church House may not have seen punches swapped before, but there has been plenty of fighting talk in the past.

During the latter half of the war it served as a refuge and alternative debating chamber for MPs who held meetings there rather than across the road as it was less visible and more secure than the Houses of Parliament, which were always a prominent target for the nightly Luftwaffe raids. And Churchill made quite a few of his inspiring "We shall fight on the beaches"-type speeches there, as well as informing the British public of the sinking of the Bismarck.

The facility was discovered by Hall of Fame boxing promoter Frank Warren‘s youngest son Henry, who works for Queensberry Promotions and was seeking a suitable site in the City of Westminster to celebrate his dad’s 40th year as a licensed promoter and in many eyes Britain's premier ringmaster, which falls next month.

Church House, which is COVID-19-secure, certainly fits the bill, and Warren will also stage there the attractive British light-heavyweight title fight between Anthony Yarde and Lyndon Arthur, which has been switched from the Royal Albert Hall, on December 5.

Saturday night will represent the final chapter in a saga that has seen April, July and October dates for the Dubois-Joyce fight cancelled because of the Coronavirus pandemic.

Warren said he was "delighted to be able to confirm such a spectacular venue to host two weeks of fantastic big-time boxing".

"Both these bouts are going to be battles for the history books, so it makes sense they’d take place in a venue so rich in history," Warren added, before claiming the impact the pandemic has had on many livelihoods was the reason for choosing against making the fight pay-per-view.

"With boxing still being held behind closed doors and struggling to get back to its feet post-lockdown, I wanted to give something of a gift to British boxing fans. Dubois versus Joyce is the best fight on the British boxing calendar and I want this to be something as many people as possible can enjoy."

So history boys Dubois and Joyce will have a lot to live up to when they settle their differences in what, because of now being under pastoral care, inevitably becomes something of a "holy war". I have no knowledge of their respective religious affiliations - if any - but one thing you can say is that neither don’t have a prayer. Even though the harder-hitting Dubois is the bookies’ favourite his fellow South Londoner has a lot going for him, too.

While I am among those who believe "Dynamite Dan" will stop the "Juggernaut" in his tracks, I would not bet my house on it. And certainly not Church House.

Joyce, 35, may be a dozen years senior to Dubois but those extra years have bought him considerably more experience, even though he has had fewer pro bouts;12 to Dubois' 15.

Dubois, whose younger sister Caroline is reckoned by many in the game to be potentially the best female boxer Britain has ever produced and a banker for Olympic gold should Tokyo 2020 get the green light next summer, had no senior amateur record to speak of whereas Joyce reached the Olympic final at Rio 2016 only to be robbed of the decision against Frenchman Tony Yoka.

Knowing the well-chronicled duplicity of ringside judging at the Games it may well be that this was a payback for what seemed to be a hometown verdict given to gold medallist Anthony Joshua four years earlier in London.

As I say the strong likelihood is that the heavier-handed Dubois will win by stoppage or knockout midway through the 12-round contest but should Joyce still be on his feet at the final bell it would not surprise me if he gained a draw - or even do his trademark celebratory backflip after his hand is raised in an unexpected victory.

What we do know is that the aptly labelled Juggernaut will keep ploughing forward, unblinking and unflinching in the face of the barrage of heavy artillery pinged at him by Dubois. This may well be his undoing, for he is open to a right hook - and Dubois’ version of that blow is something special, one devil of a punch which has flattened all but one of his opponents, the veteran American Kevin Johnson who passively went the distance.

What we do not know is whether Dubois can take it as well as dish it out. His chops have never been tested with a solid punch and Joyce can bang a bit as well as box.

Joyce has swapped Las Vegas for Surbiton as a training base for this fight, where he has slimmed down to look sleek and fighting fit. Interestingly both have used the services of American heavyweight Jeremiah Milton who sparred many rounds with Joyce in Vegas on his previous training stint before being flown in to work out with 23-year-old Dubois at the new state-of-the-art Peacock Gym now relocated to Epping.

Milton is on record as saying he favoured Joyce to win because of his staying power and victories over a "better class of opponent", such as former world champion Bermane Stiverne and two-time title challenger Bryant Jennings. Whereas Dubois’ most impressive conquest was of that of Nathan Gorman for the British title.

But since taking a few explosive punches from Dynamite Dan. Milton seems to be hedging his bets.

Whatever, this is the most fascinating domestic heavyweight dust-up since Lennox Lewis stopped Frank Bruno and before that that Henry Cooper lost controversially to Joe Bugner.

For one of them, it will be their finest hour, as Churchill memorably put it, and no doubt blood, sweat and perhaps even tears will be shed in a ring war that has already made fistic history.

We can anticipate a lockdown knock-down - or two - in an ecclesiastical environment that should certainly expect to see someone on their knees!