The following season, as an 18-year-old, Bowyer made 33 full league appearances and one as substitute for City as they finished 11th in the First Division. He was also a regular in Manchester City's League Cup run and scored twice in their two-legged semi final against local rivals United. In March he came on as a substitute for Mike Summerbee in the 1970 Football League Cup Final beating West Bromwich Albion 2–1. Manchester City also won the Cup Winners Cup that season and Bowyer played his part in that European success too. City overcame Athletic Bilbao in the first round, 6–3 on aggregate with Bowyer playing in both and scoring in the second leg 3–0 home win. He also played in both second-round games against Belgian club Lierse S.K. but missed out on the next two rounds. He replaced Mike Doyle after 23 minutes in the 1970 European Cup Winners' Cup Final against Górnik Zabrze in Vienna. City won 2–1.