Birtles kept his place for the rest of the season capping his success with two goals in the 3–2 win over Southampton in the 1979 League Cup Final.
He also won a 1979 European Cup winner's medal via the 1–0 victory over Malmö FF of Sweden in Munich's Olympic Stadium.
[3] He gained another winner's medal in the following season's European Cup against Hamburg providing the return pass from which John Robertson scored the only goal.
[3] He began the 1980–81 season in fine form, scoring six goals in nine league games for Forest, before a £1.25 million fee took him to Manchester United.
[4] Under manager Dave Sexton, Birtles made his debut for Manchester United in a First Division victory over Stoke City at the Victoria Ground on 22 October 1980.
During the final months of his first spell at Nottingham Forest, when he was still reputed as one of the English league's finest strikers, he was capped three times at senior level for England.