The first real danger from the visitors came in the 14th minute when Martos broke away and Voordeckers headed his cross wide of the target. Aberdeen responded with Black coming close when his shot on the turn was deflected over the bar. Minutes later it should have been 3-0 to the Dons when McLeish headed against the post following a Strachan free kick. Waterschei continued to look dangerous on the break and Leighton had to look alert to save from Pierre Janssen. The Dons had to defend stoutly as the Belgians forced three corners in quick succession, before a Strachan cross after 42 minutes sparked a melee in the Waterschei goal.
Aberdeen by this stage were dominant and the crucial third goal arrived in the 67th minute. An alert Mark McGhee turned, his defender once again and found his way through and his angled cross went beyond Pudelko. Two minutes later the Belgians were once again on the ropes as the Dons made it four. McGhee turned provider on this occasion. The Dons' striker weaved his way down the right and his perfect cross was headed home as Peter Weir scored with a superb dive. It was no more than the Dons deserved in a game they had really kept up almost relentless pressure on their visitors in every area of the park.
Waterschei pulled a goal back in the 70th minute Voordeckers crossed for Gudmundsson to head past Leighton at the near post. Aberdeen responded by making a double substitution in 78 minutes. Cooper and Hewitt replacing Doug Bell and Eric Black whose contributions had been immense. The Waterschei goal had a remarkable escape three minutes later when a Kennedy cross ran along the goal line with Cooper only inches away from making contact. The pressure was still on and with six minutes left the Aberdeen goal machine was at it again. Mark McGhee was persistent if not clinical when he had no less than three attempts to finally squeeze the ball past a desperate Pudelko.
Waterschei coach Kunnecke was understandably shocked - "It is finished. I don't think there is any team in the world that could take four goals off of Aberdeen. They simply swept us aside." Among the spectators was Real Madrid coach Luis Molowny who kept company with most of the big names in Scottish football. He said, "I was very impressed by Aberdeen. Their ability, power and strength were awesome. We did not know too much about Aberdeen before the tie, if it turns out to be a Real Madrid v Aberdeen final I expect it to be a very tough game."
Amongst the crowd at Pittodrie were Jock Stein, former England boss Sir Alf Ramsey and a host of admiring Scottish football managers. Archie Knox, who had seen Waterschei before the tie explained - "I thought that if we could get at them early we could really do some damage and so it proved 5-1 is an exceptional result in a European semi-final."