Celtic’s centenary season league and cup double of 1987/88 has to go down as one of the most memorable in the club’s history, partly because it was so unexpected.

The season before – 1986/87 – had seen Rangers appoint Graeme Souness as manager, and after signing the high-profile trio of Terry Butcher, Chris Woods and Graham Roberts, the Ibrox side won the league, and Celtic boss Davie Hay left his position at the end of the season.

The Hoops appointed former manager Billy McNeill as Hay’s replacement, and his return to the club had the desired effect. The players McNeill bought – such as Frank McAvennie, Andy Walker, Billy Stark, Chris Morris and Joe Miller – might have been cheaper than their Rangers counterparts, but they were able to get the job done as the Hoops won the league title, with the Ibrox side in third place behind Hearts.

With the league won, thoughts turned to the Scottish Cup Final, where the Bhoys would be looking to complete a league and cup double against a Dundee United side which had yet to win the tournament.

The game, which was played in blazing sunshine, was cagey, as few chances were created in the first-half.

It was a different story in the second-half though, as the Tannadice side started to take control of the game, and they took the lead in the 49th minute.

Striker Kevin Gallagher latched on to an Eamonn Bannon header, and outpaced Roy Aitken before hammering a shot high into the net, past Allen McKnight. Aitken couldn’t challenge Gallagher as he had already been booked and could have been sent-off if he pulled back the striker.

The Hoops’ double dream looked to be fading until the 76th minute, when Anton Rogan’s cross was misjudged by goalkeeper Billy Thomson and Frank McAvennie was on hand to head the ball into the back of the net.

The game looked to be heading to extra time, but Celtic and McAvennie had other ideas. The Hoops were awarded a corner in the 90th minute of the game, and McAvennie took up a good position in the penalty box.

The corner was played in low, and Billy Stark’s effort on goal was blocked. The ball then broke to McAvennie, who lifted the ball over the despairing Thomson, and into the back of the net, to clinch a 2-1 victory.

YouTube: Celtic 2-1 Dundee United | 1988 Scottish Cup Final Goals

After scoring the goal McAvennie dropped to his knees in celebration, as the Hoops fans and players celebrated wildly. Manager Billy McNeill wanted his players to keep their emotions in check, and make sure they didn’t give away an equaliser. The Bhoys repelled one last United attack, and the celebrations began in earnest as the final whistle blew.

It was an incredible way to cap off a memorable season for the club. Not only did the Hoops manage to win the league, but they also captured the Scottish Cup in the most dramatic of circumstances.

Winning a cup with a last-minute goal is a great way to clinch the league and cup double, and it is a moment that any Celtic fan who watched the game will never forget.