The famous night in Rotterdam in 1991 saw the Reds overcome the odds to beat Johan Cruyff's strong favourites 2-1 and there are echoes of a similar situation at Wembley in this season's Champions League final.
After winning a first trophy thanks to the FA Cup a year earlier, the European triumph was a key factor in continuing the momentum that would propel the Reds to an unparalleled spell of domestic dominance and two Champions League trophies on foreign soil.
"It was a major step forward," Sir Alex replied to Inside United when asked about the significance of the Cup Winners' Cup success. "There's no doubt about that.
"Sharpey [Lee Sharpe] was coming through, so was Giggsy [Ryan Giggs]. We had Sparky [Mark Hughes] and Choccy [Brian McClair], [Paul] Ince and [Bryan] Robson and, soon after, we bought Paul Parker, Andrei Kanchelskis and Peter Schmeichel.
"Those were fundamental purchases that gave us a really strong group."
The match itself was something of a battle with Hughes scoring twice against his former club only for United to need to dig deep when Ronald Koeman pulled one back with Clayton Blackmore making a saving clearance towards the end.
With so much focus on the manager's tactics at Wembley after the 2-0 defeat to Barca in Rome in 2009, he gave an insight into that memorable evening in Holland.