Sir Alex Ferguson has highlighted United's San Siro victory as the firing-pin in their Euro campaign. The 3-2 success in Milan three weeks ago was the first time United had won in the Italian city against the Rossoneri in four attempts. Matt Busby's United had failed twice in the 50s and 60s. Ferguson was unable to succeed in 2005 and '07 but the win in the first leg of the Champions League last 16 can provide the same confidence shot in the arm the 90s side had when they finally overcame the then Italian superpower Juventus. "Winning for the first time in Milan against AC in four attempts I was delighted with because historically you are playing one of the best teams of all time in Europe," said Sir Alex. "It was certainly without doubt a landmark victory for us. You can't go without thinking that was a really, really important thing for us. "The psychological boost of going there and winning is great. Winning that game was fantastic for us. It was a step forward for us I think." The majority of his United squad have the experience of a European Cup final success in Moscow on their CV and last May's defeat in Rome. But because of the ever-changing face of the Champions League challenge Fergie believes the win against AC Milan in the San Siro was vital. "European football is one of a changing nature every year," he says. "The challenge to me seems to get different because it is a varied tournament in the sense that club form changes. "The Italians for a few years have not been as good as the Spaniards or the English teams. However, having watched the Milan derby there is a sense they are better now. "The challenge we had last season included Barcelona and they beat us and were the better team on the day in the final but I think there is a little shift now. The Italian teams are better this year."