 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.Again Byrne was on the scoresheet in the Cup Winners' Cup, in the second round against Olympiacos, the third round against Magedeburg and in the semi-final against Borussia Dortmund where they were eliminated from the competition.