Ian Porterfield's expression after hooking the decisive goal past the Leeds keeper David Harvey, Jim Montgomery's incredible mid-air twist to deny Peter Lorimer a certain goal, Bob Stokoe's dash across the Wembley turf into the arms of Montgomery, a moment of unbridled joy later captured in bronze outside the Stadium of Light: the victory of second-division Sunderland over Don Revie's mighty Leeds United in the 1973 FA Cup final was replete with iconic images.

It was, in the captain Bobby Kerr's words, "a victory for a one-club city, where literally everyone, from miners to shipbuilders to shop workers drove us onwards." The football club was the face of the whole town. "Even now," the forward Dennis Tueart said, "men and women of a certain age are moved to tears when they talk to you about the game. Our run to the final, and the final itself, created a perfect pitch between the club, its fans and the entire city." In the build-up to the match, documentaries were broadcast by the BBC and Tyne Tees Television that captured perfectly just what was happening in Sunderland and precisely what it meant to everyone connected with the town.

The BBC commissioned Harold Williamson, born in Houghton-le-Spring, to present and narrate a programme called The Pride and Passion of Sunderland. Broadcast on the Thursday before the final, when Tueart, Porterfield and the striker Billy Hughes were meeting Suzi Quatro and The Sweet as guests of honour at the Top of the Pops studio, the BBC documentary focussed mainly on the impact of the manager — and former Newcastle defender — Bob Stokoe, and how his galvanising presence had lifted the spirit of the town against a backdrop of high inflation, strikes and the impending energy crisis. "Bob was a people person," said Tueart. "One of the first things he did at the club was change the day of midweek home matches so that shipyard workers could attend games. He also changed the kit so we played in black shorts [rather than white, which had been introduced in 1961], which pleased older fans. He understood and connected with supporters in a subtle way."

A young John Motson was dispatched to Wearmouth Colliery, where miners who'd just completed their shift spoke glowingly about Stokoe. "He's saved this town," claimed one. Asked by Motson why he believed Sunderland would defeat Leeds, another miner replied incredulously, "Because we're the better team." Although a brief segment of the Motson interviews survives, The Pride and Passion of Sunderland fell victim to the BBC's purging of the archives in the late 1970s. Fortunately Tyne Tees's offering, Meanwhile Back in Sunderland, remains fully preserved and is arguably the most treasured social documentary to emerge from the North East.

"I went to see Bob Stokoe and chairman Keith Collings," said the head of features at Tyne Tees, Leslie Barrett. "It soon became fairly clear that we weren't going to get into Wembley, and the BBC and ITV had the team hotel covered to the hilt." So Barrett was forced to think outside the box, and opted to shoot footage in the town from 5am to midnight on Cup Final Day, using four different camera crews. He decided that there wouldn't be a narrator; the people of Sunderland would provide their own narrative to the day. Although the production team was initially disappointed not to be going to Wembley, Barrett tapped into the waves of enthusiasm sweeping through the town and insisted, "If we win, we have got a hell of a programme here."

At daybreak on the morning of the game, the players were sleeping soundly in their Selsdon Park Hotel beds. Some, like Hughes, had supped a couple of cans of lager the night before to ease their nerves; Stokoe, riled by ITV's Who'll Win The Cup? late-night show, on which panellists Jack Charlton, Malcolm Allison and Pat Crerand predicted a comfortable Leeds victory, tossed and turned. Leslie Barrett's filming crews, meanwhile, were already hard at work on the streets of Sunderland. By 5.30, groups of supporters, clad in giant red-and-white rosettes, natty red-and-white hats and, for the majority of male supporters, suits, were making their way to the fleet of Wembley-bound coaches, heading south to the A19, and the station, where specially laid on trains headed to Kings Cross via Newcastle. "About a week before the final," recalled Stokoe, "the town had simply run out of red and white material. You couldn't get a scarf or a rosette anywhere." The documentary explains the shortage: as fans trooped down the streets, virtually every shop window had some kind of candy-striped display; in clothes shops wax dummies were clad in Sunderland garb. Even the undertakers had a discreet rosette tucked to one side.

The FA Cup final was arguably sport's biggest televison event of the year in the seventies, often attracting in excess of 20 million viewers across both BBC and ITV. The BBC commentator Barry Davies argues that the 1973 final was the first time the two broadcasters had really tried to outdo one another with the build-up. ITV were granted a live feed on the Sunderland team bus (Revie refused to allow cameras onto the Leeds bus) and although the technology broke down on more than one occasion, it showed the team in a decidedly relaxed state. They were still grinning about Hughes setting off a "laughing box" during the team's interview with Davies earlier that morning. The players dissolved into fits of giggles on live TV, much to Davies's astonishment. The players' antics contrasted with the far more sombre BBC interview conducted with Revie's squad, who wore pin-striped suits. The Sunderland team watched the Leeds interview on Cup Final Grandstand before leaving for Wembley and Dave Watson recalled the "dread and fear" on the Leeds players' faces. Having watched the tense interview, Tueart became "even more convinced that the day would be ours."

Back home, the locals closed up their shops and descended upon those neighbours who were fortunate enough to own colour televisions. Local boys, accompanied by a dog with a rosette pinned to its collar, had a kickabout in a side street within a few yards of Roker Park and large groups began clustering around Vision Hire on Fawcett Street for an impromptu street party. When the game kicked off at 3.00pm, the town was deserted but for a solitary policeman trudging a lonely beat. Television viewers saw the players emerge from the tunnel on a gloomy London afternoon, with Bobby Kerr, the smallest-ever FA Cup Final captain, surging ahead of his counterpart Billy Bremner. Kerr was yelled at by Jim Montgomery to slow down and his teammates, barely able to control their glee, bounced up and down as they prepared to meet the Duke of Kent.

When Porterfield scored after 31 minutes, the emotion of Sunderland fans at Wembley was mirrored in the houses and streets at home. Plastic hats were thrown into the air, beer was slopped over tables in pubs, working men's clubs and cinemas which broadcasted the game, and teenage girls screamed and wept. The reaction among fans to Montgomery's remarkable double save was one of bafflement initially, because it took so long to understand what had happened. Jimmy Hill, co-commentating, only realised Montgomery had saved Lorimer's shot when he saw a second replay.

As the game reached its climax, the atmosphere was fevered. Many could barely watch, others chain-smoked; some chain-smoked while not watching. The final whistle was met with a tumult of Klaxons, whistles, and cars tooting their horns. On the streets, groups of women performed renditions of "Ee aye adeo, we won the cup," and men embraced, according to one fan, "in a way Sunderland blokes have never done, except perhaps when we last won the cup in 1937." With the players preparing for their reception at the Savoy, the town partied in inimitable early seventies style. A young woman revealed knickers embellished with Sunderland logos and men with Rod Stewart-style feather cuts got more beers in. Most poignantly of all, a group of senior citizens sang along to a pling-pling version of You'll Never Walk Alone, led by a pianist clad in an enormous red-and-white top hat and a drummer with red-and-white twirling drum sticks. "Whenever I see that final clip on the documentary," Tueart said, "I watch it with a lump in my throat, because those older supporters are long since passed away. Many of them had been to the Raich Carter Final of '37, and couldn't believe it when, 36 years later, Sunderland did it again."

Due to Sunderland's backlogged fixture list, they had to travel to Cardiff on Monday (the game ended 1-1) before coming back home on Tuesday, in advance of their final league game of the season against QPR (an understandably exhausted group of Sunderland players were hammered 3-0 by the Second Division runners-up) at Roker Park on Wednesday. "None of us had a clue about what had been going on at home," explained Watson. "We'd been in our Wembley bubble." As the team approached the town, they had a taste of what was to come. "There were supporters hanging over bridges, and cheering from the grass verges. There were cows in fields wearing rosettes and when we got into Sunderland, there were tens of thousands out and Roker Park just buzzed for the trophy parade." Lance Hardy, author of Stokoe, Sunderland And '73, estimates that around 750,000 turned out to welcome home the conquering heroes, and thanks to a local amateur film maker, grainy images remain of the Roker Park homecoming, at which around 50,000 crammed in to see the cup paraded. For those who missed it, there was always the QPR game the following night, at which Stan Bowles allegedly knocked the FA Cup off a table by the side of the pitch for a bet, enraging the 43,000 who had squeezed in.

Meanwhile Back in Sunderland was broadcast on the Monday and when the players watched it at a private screening, they were staggered by what they saw. "We'd been out and about in the town during the cup run, meeting and mixing with supporters, so we had a feeling what might have happened, but the documentary reaffirmed exactly how the whole town was involved," said Watson. Only Yorkshire TV and Wales bought the rights to the programme, but it is occasionally repeated in the area now and is accessible on YouTube in all its glory. Several former players still watch it from time to time, Hughes describing it as "a perfect piece of TV, simple and effective". Stokoe, whose Wembley dash is included at the end of the documentary, is said to have wept when he saw it.

Towards the end of the programme, several supporters insist: "We'll win it next year," and Sunderland were installed as promotion favourites for 1973-74. Things quickly went awry. Tueart and Watson departed to Manchester City and the class of '73 disintegrated amid grumblings about a lack of investment in the team by the board. Stokoe guided the team to Division One three years later but, stricken by ill-health, resigned after a disappointing start. Sunderland, who were losing finalists to Liverpool in 1992, have been unable to match the ecstasy of the '73 final since, but as Tueart notes, "That would be nigh on impossible. You can't recreate what happened back then."

Kerr once described the '73 Cup run as "something that you cannot put into words." Yet, thanks to Leslie Barrett's brilliant improvisation, Meanwhile Back in Sunderland does a splendid job of encapsulating the joyous mood of the time and will remain a compelling oral and visual testament to the bewitching power the FA Cup held over Sunderland in 1973.

This article appeared on Episode Sixty Eight of the Blizzard Podcast. You can see which other articles we have featured by searching the Podcast tag, but we'd really like you to subscribe which you can do through iTunes, Soundcloud, our RSS feed or wherever you usually get your podcasts of choice.