 Irvine took his goalscoring form into the cup competitions, netting five times in three FA Cup ties, and scoring the winning goals against Southampton and Stoke City as the team reached the fifth round of the Football League Cup before being knocked out by Peterborough United.During the second half of the season, he went through a somewhat barren spell, failing to score in the league between 8 January 1966 and 26 March 1966.He ended his poor run of form with a hat-trick in the 4–1 win over Nottingham Forest at Turf Moor.