Throughout his club career, Annovazzi played for A.C. Milan, Atalanta, Anconitana, Pro Patria and Città di Castello. He made his Serie A debut with Milan in a 1–1 away draw against Modena on 16 December 1945. He was a member of the Milan side that won the 1950–51 Serie A title, after a 44-year title drought, as well as the Coppa Latina; he contributed to the team's title success by scoring 17 goals throughout the season, 16 of which came in Serie A, and one in the Coppa Latina.