THE challenge facing Aberdeen in the William Hill Scottish Cup at Hampden tomorrow is a considerable one which few hold out any hope of them rising to meet.

They must overcome a Celtic side whose players and manager are well on the way to attaining legendary status as a result of their historic achievements to date and who will complete a domestic treble if they triumph. It is a tall order.

It has, however, been done before.

Back in 1970 the Pittodrie club was widely expected to be beaten, and beaten comfortably, by their Parkhead rivals in the final. With very good reason.

Read more: Six of the best Scottish Cup finals: Aberdeen 3 Celtic 1 (1970)

Jock Stein’s team that day comprised many of the players, Tommy Gemmell, Jimmy Johnstone, Bobby Lennox, Billy McNeill, Bobby Murdoch and Willie Wallace, who had lifted the European Cup just three years earlier.

What is more, they were also bidding, after securing the League Cup and winning the Scottish title for the fifth consecutive season, to complete a clean sweep of domestic trophies for the second year running and for the third time in four years.

Yet, Aberdeen ran out comfortable and deserved 3-1 victors - thanks to a first-half Joe Harper penalty and two strikes from Derek McKay, who lived up to his nickname “Cup Tie McKay”, late on - in front of a crowd of 108,434.

For Arthur Graham, the teenage Celtic fan from Castlemilk who was, much to his delight and astonishment, handed a start by Eddie Turnbull, the Aberdeen manager, despite only being involved in a smattering of first team games, that result proves an upset is possible.

“Let’s hope Aberdeen can repeat that victory,” he said. “Aberdeen are always underdogs against Celtic and they will be this weekend. But that was certainly the case in our day and we managed to beat them in the 1970 Scottish Cup final, the 1971 Drybrough Cup final and the 1976 League Cup final. We played them in three finals and beat them in three finals. It can certainly be done.”

Graham, a skilful and pacey winger, enjoyed a long and distinguished professional career at a high level with Aberdeen, Leeds United, Manchester United and Bradford City and also represented Scotland, who weren’t exactly struggling for options in his position at that time, on 11 occasions.

Read more: Six of the best Scottish Cup finals: Aberdeen 3 Celtic 1 (1970)

However, his involvement in that Scottish Cup final at the age of just 17 was quite unexpected. Perhaps the impact which he had made on his Aberdeen debut against Celtic a couple of months earlier convinced Turnbull to take a chance on him.

“I had only moved to Pittodrie that January,” said Graham, now 64 and living down in Yorkshire where he continues to coach youngsters at Leeds United. “I had got a new pair of boots when I joined and ended up getting blisters on my feet and spending a spell out. I made my first appearance for the first team around March.

“It was in a game against Celtic at Parkhead. We won 2-1 and I scored the winning goal. All my family were mad Celtic fans, as I was myself, and they were all at the game. They collared me afterwards. ‘What the hell do you think you’re playing at?’ was the gist of it. It was quite hard to believe what had happened.

“But I didn’t play in any games leading up to the cup final. I didn’t really think I would be involved. It was a pleasant surprise when I got the nod to play.”

Graham, though, certainly justified his selection by setting up McKay for both of his goals with crosses from out wide on the left. He believes that Turnbull, a member of Hibernian’s fabled “Famous Five” forward line, deserves enormous credit for his success that afternoon.

“I was 17, had just moved up to Aberdeen from Glasgow and was probably a little bit full of myself,” he said. “Eddie quickly put me in my place. He went through me a couple of times for different things that I did. You never crossed Eddie. You could have a laugh with him, but he was a strong character. He didn’t mess about.

“He also knew his football. He had obviously been a smashing player himself and he understood the game. He had a lot of confidence in me. He just gave me encouragement all the time and filled me with confidence. He would say to me: ‘Have a go, take your player on’. In those days wingers were expected to beat your full-back. I just couldn’t wait to get out there. He probably saw that.

Read more: Six of the best Scottish Cup finals: Aberdeen 3 Celtic 1 (1970)

“A lot of the Lisbon Lions were still in that Celtic side. Jimmy Johnstone was on my side of the park. They were still so dominant. As I say, nobody expected us to win. It was quite a challenge. But we had a smashing team as well with some great players.

“We had Bobby Cark, Jim Hermiston, Jim Forrest, Joe Harper, Martin Buchan. Then we had “Cup Tie” McKay. He scored goals all through the competition. He was an out and out winger too. He played on the right and I played on the left. He just had one of those spells. Every time he played he scored. I think he scored in every round that year.

“We scored a penalty early doors and that gave us a lot of belief. We ran out worthy winners in the end. There were over 100,000 people in the stadium that day. It was some experience.”

Graham had six brothers and three sisters and a fair few of them, along with assorted cousins, aunts and uncles from his extended family, were in with the Celtic fans that day. So did he have to face their wrath once again afterwards? “No, we got straight on the bus, opened up a few bottles of champagne and went back to Gleneagles where we were staying,” he said.

Turnbull informed his Aberdeen players he had seen a crate of bubbly being delivered to the Celtic dressing room before kick-off. But Graham believes that was just pre-match psychology. “I think he probably just made it up to get a reaction out of us, to wind us up,” he said.

Graham returned to Pittodrie back in October to attend a 40th anniversary reunion of the Aberdeen team which defeated Celtic 2-1 in the League Cup final in 1976 and he took in a league meeting between the two finalists.

Brendan Rodgers’s team dominated the match and won thanks to a Tom Rogic goal that day. But their former player saw enough of Derek McInnes’s side to make him believe they are more than capable of emulating the famous triumph which he was involved in.

“People can be quite dismissive about the Scottish game down here,” he said. “I always tell them that if Celtic came down to England they would win the title every season. They obviously have some great players at the moment, Scott Sinclair especially.

“But I was impressed by Jonny Hayes as well. He is a real old-fashioned winger, very direct. Aberdeen have done well under McInnes. I always check for their result and it has been great to see them up there these last few seasons. It will be difficult, but there’s no reason they can’t do it.”