I was in Manchester that day, just another wide-eyed teen harbouring dreams of future stardom. The football club had paid for my flights and accommodation, just a couple of miles from Old Trafford.
That afternoon, West Brom, riding high at the top of the table, would stride onto the hallowed turf. But this young Red Devils diehard wouldn't be there to see it.
The club that had flown me to Manchester was City, not United.
And, as part of a 'get to know you' exercise (they ultimately 'got to know' that I wasn't any good), I found myself on an early morning coach to Ashton Gate, 160 miles away, where Man City played out an instantly forgettable 1-1 draw with their Bristol counterparts.
On the way back, the travelling hordes savoured incoming news that West Brom had hammered five past United.
The guy on the radio maintained, however, that the Reds had played their part in a ding-dong First Division encounter, but had been undone by the brilliance of Baggies strikers Laurie Cunningham and Cyrille Regis.
God, how I regretted not being at that game, even though United had lost.
Cunningham and Regis, both of whom are, sadly, no longer with us, were my favourite non-Reds; why on earth hadn't Old Trafford manager Dave Sexton signed them?
Instead, we had Jimmy Greenhoff and Andy Ritchie up front. Decent players and popular too, especially Jimmy, but neither of them had the grace and balletic elegance of will-o'-the-wisp Cunningham, nor the explosive pace and sheer raw power of Regis.
Extended highlights of the game were shown on ITV Granada that Saturday night.
I had a fair idea of what I was about to see, but couldn't believe what I ended up hearing.
Boos and monkey chants rained in every time Cunningham, Regis or Albion defender Brendan Batson received the ball on that snowbound pitch.
A shameful, appalling episode. Although untrammelled cacophonies of hatred had cascaded down from the OT stands before, they were noticeably and despicably ramped up by the resident imbeciles on that day in particular - December 30, 1978 - because the visitors happened to be the first English club to have three black players in the same team.
Bad call. The abused players karmically shoved the relentless bile back down the throats of the knuckle-draggers during what is now regarded as, hideous soundtrack notwithstanding, one of the best ever top-flight matches. It was certainly a pivotal one.
Cunningham's mesmeric, virtuoso act of retribution that day, following an opus maximus against Valencia in the Uefa Cup earlier that month, convinced Real Madrid (Los Blancos; ah, the irony) to shell out a then eye-watering £950,000 for the 22-year-old Londoner.
United bigwigs, meanwhile, began fluttering eyelashes at Albion's flamboyant boss Ron Atkinson, who would eventually replace Sexton in 1981 and, finally, bring black players to the club - including an injury-ravaged Cunningham on loan.
(Prior to that, Dennis Walker - one first-team appearance back in 1963 - had been the only black player to don the red shirt).
When asked on TV after that epic 1978 game who his man of the match was, Big Ron replied: "It's a toss up between one of the coloured front people".
A quarter of a century later, Atkinson's reputation would be irrevocably damaged by the inadvertent broadcast of a grossly offensive remark about French international Marcel Desailly.
He might have got away with it in the 1970s, though.
Back then, the odious National Front was gaining in support and the most popular TV shows included The Black & White Minstrels and sitcoms Love Thy Neighbour and Till Death Do Us Part , both of which had ignorant racists as their main characters.
Comedian Jim Davidson's 'Chalky White' faux Jamaican alter ego helped make him a household name, while Kenny Lynch made a fortune by allowing himself to be racially abused 'for laughs' on prime time entertainment.
A month before that ignominious afternoon at Old Trafford, Viv Anderson made global headlines as 'the first black man to play for England' (although some will argue that mixed-race Leeds United defender Paul Reaney had beaten him to it a decade earlier).
What was happening in the rest of the UK felt 'normal' to us Northern Ireland folk, who were preoccupied by a different strand of bigotry in those days.
Across the water, however, footballers like Cunningham were all too aware that antipathy towards them went way beyond moronic mouthpieces on the terraces of Old Trafford and other grounds.
One night in 1978, Cunningham was walking in Birmingham with girlfriend Nikki Brown when the pair were accosted by a trio of Neanderthals. One spat at Nikki, calling her a disgusting racial epithet, while the other two laid into her young black partner, who'd taken exception to the vile abuse.
Laurie got the better of one, leaving him bloodied on the pavement, and was about to smack him again when Nikki screamed: "Don't Laurie, it's not worth it".
At this point, Horizontal Moron looked up. "Laurie? Laurie Cunningham? Christ, it's Laurie Cunningham! We're Baggies, man, we love you! Any chance of an autograph, mate?"
Thank goodness it's 2020 and racism is no longer an issue...