A varsity baseball star at Texas Tech, Ault was signed by the Rangers in 1976 as an amateur free agent and played nine games for the Rangers. In 1977 he joined the new Blue Jays franchise through the expansion draft and earned a spot in team history when he hit two home runs in the team's first game, including one in the first inning. At the time Ault's feat tied a major league record for the most home runs in an Opening Day game (since broken by George Bell, coincidentally also a Blue Jay, and Karl Rhodes.)
Ault suffered injuries and ineffectiveness in 1978 and 1979 and left the major leagues.