Thirty-five years ago today, Scotland secured a momentous result that should have sparked an outpouring of joy. Instead, the events at Cardiff's Ninian Park precipitated an unprecedented period of national mourning.

For the previous two decades, as Scotland's clubs conquered Europe and its national team reached the first of five successive FIFA World Cups™, Jock Stein had been the dominant figure. To many, this former miner seemed to embody everything that enabled his small country to consistently punch above its weight. He had certainly led the way in showing that anything was possible, winning the European Cup in 1967 with a Celtic team comprised entirely of players born within a 30-mile radius of the club’s stadium.

Bill Shankly, his great friend, famously told Stein that this achievement made him “immortal”. But while Scottish football without Big Jock seemed impossible to envisage in those halcyon days, a chilly night in Cardiff imposed that unthinkable reality on a stunned nation.

By 1985, and as unlikely as it may seem now, Scotland had become almost blasé about reaching the World Cup. The Tartan Army had, after all, marched to the global showpieces of 1974, 1978 and 1982, when Stein's team came within goal difference of advancing to the latter stages at Soviet Union's expense.

But the Scots arrived in Wales on the brink of elimination. Ian Rush's solitary, match-winning goal in the corresponding fixture at Hampden meant that the hosts stood within two points of securing second spot behind Spain, and a place in a UEFA/OFC play-off. Shorn of stars such as Kenny Dalglish, Steve Archibald, Alan Hansen and his captain, Graeme Souness, Stein knew that his side went into the match as clear underdogs.

Sir Alex Ferguson, Big Jock’s then assistant, saw the strain visibly etched on his mentor's face as kick-off approached. And there was to be further fraying of nerves when, with just 13 minutes played, Wales' early dominance was rewarded with an opening goal from a future Ferguson protégé, Mark Hughes.

The situation hardly improved at half-time when goalkeeper Jim Leighton, who had performed hesitantly in the first half, dropped the bombshell that he had lost a contact lens during the action and had no replacement. But while the enforced introduction of Alan Rough restricted his tactical options, Stein's words roused Scotland to a fightback that quickly had their hosts on the defensive. Then came the bold decision to replace Gordon Strachan with Davie Cooper, entrusting the talented but unpredictable Rangers winger with unlocking a resolute Welsh defence.

Cooper justified that faith, calmly slotting a penalty past Neville Southall with nine minutes remaining as the mounting tension became unbearable. Then, as the final, fateful seconds ticked down – mistakenly thinking the referee had brought proceedings to an end – Stein clambered to his feet and suffered a massive heart attack. Within minutes, one of Scotland's greatest heroes had been pronounced dead in the Ninian Park treatment room.

A band of 12,000 Scottish fans had travelled to Cardiff and, as news spread and Ferguson broke the news to a disconsolate dressing room, these same fans stood silently, disbelievingly, outside the doors of Ninian Park. One supporter, interviewed on television, summed up the prevailing emotion. "We'd rather be out of the World Cup and have big Jock back," he said quietly to the camera.

Yet Scotland did go on to the global finals, with Ferguson – who took the reins in Mexico – leading the team to a gritty 2-0 play-off win over Australia. In Glasgow, meanwhile, thousands lined the streets for Stein’s funeral, bidding farewell to an era-defining national icon.

"It's not a night I want to remember. I had thought at the time that he wasn't at his bubbly best. He wasn't as sparky as usual at the dinner table. He was still able to make big decisions though. He started out making great decisions and he went out with a great decision – taking me off! We were 1-0 down and the man he replaced me with went on to score the equaliser... Some say people worshipped big Jock, but it's better than that. People loved him." Gordon Strachan, former Scotland midfielder

"I remember the feeling of elation when Coop's penalty went in. We were celebrating on the pitch at the end when Alex Ferguson came over and said, 'Big Jock's taken ill. Keep the boys on the pitch'. We were worried and concerned but no more than that. It all changed when I got into the dressing room. I saw our masseur, Jimmy Steele, in tears. At that moment I knew. No-one had to tell me Big Jock had gone. We saw thousands of Scots fans on the way to the airport, but none were celebrating." Richard Gough, former Scotland defender

“Alex Ferguson said two words: ‘Jock’s dead’. We’d been jumping up and down, patting each other on the back, celebrating. We had got a play-off to get through with Australia, but we’d done the hard work – we were going to the World Cup. Then Alex opened the door, he came in and it fell silent as he made his two-word statement. There wasn’t a murmur. When we started asking, ‘How?’ and ‘What happened?’, Fergie was gone again – he couldn’t say any more.” Alex McLeish, former Scotland defender

"I didn't shed a tear until I had flown from Cardiff to Glasgow and set out on the drive to Aberdeen. On the way up, I pulled into a lay-by and just broke down... For people like myself, Jock was the precursor of all the deeds and challenges we needed to aim at. He would never take the praise himself. It was always about the players and how great the team were. That magnanimity tells you everything about him. For any man seeking to further his education in football, Jock Stein was a one-man university." Sir Alex Ferguson, Stein's then assistant.