On April 7, 1977, Ault was the Blue Jays' starting first baseman versus the Chicago White Sox, in the team's first professional game. In bottom of the first inning, Ault, batting third in the lineup, slugged the first home run (and first hit) in Blue Jays' history off White Sox starting pitcher Ken Brett. He hit another home run off Brett in the third inning, tying a major league record for most home runs in an Opening Day game. Those were the first two home runs of Ault's career (Ault also had an RBI single and a walk in the game), and the Blue Jays defeated the White Sox 9-5. George Bell of the Blue Jays broke the record when he hit three home runs on Opening Day in 1988, and was matched by Tuffy Rhodes of the Chicago Cubs in 1994 and Dmitri Young of the Detroit Tigers in 2005. Ault was covered with "immediate acclaim and nationwide publicity" as a result of the feat.