The 1989 Toronto Blue Jays season was the franchise's 13th season of Major League Baseball. It resulted in the Blue Jays finishing first in the American League East with a record of 89 wins and 73 losses. The Blue Jays' ace pitcher Dave Stieb led the staff with 17 victories, and the team was offensively buoyed by the league's home run king Fred McGriff. Toronto won the AL East pennant in the final weekend of the season against the favored Baltimore Orioles. The Blue Jays lost the ALCS in five games to the eventual World Series champion Oakland Athletics. It was the team's last season at Exhibition Stadium, before moving to SkyDome halfway into the season. The Blue Jays hit eight grand slams, the most in MLB in 1989.