From 1966 through 1970, Watson appeared in less than 100 games each season for the Astros, batting .259, with 14 home runs, and 74 runs batted in (RBI) overall. From 1971 through 1978, Watson appeared in at least 129 games each season, batting .303, with 122 home runs, and 690 RBI altogether. He was selected as an All-Star twice; in 1973 and 1975. On June 24, 1977, Watson hit for the cycle in a 6–5 win over the San Francisco Giants. In total, during his 14 seasons with the Astros, Watson appeared in 1,381 games, batting .297, with 139 home runs, and 781 RBI.