 Byrne scored in the first round against La Gantoise, the third round against Lausanne and a goal in the semi-finals against Real Zaragoza.Unfortunately, for Byrne, he was injured in the England-Scotland match a few weeks earlier and did not play in the final against Munich 1860 at Wembley Stadium which West Ham won 2–0

In the 1965–66 season West Ham were again in European football as holders of the Cup Winners' Cup.They also reached the 1966 League Cup Final.