When Monday was mostly a utility player he played a role in the deciding Game 5 of the NLCS at Olympic Stadium in Montreal. Played on a Monday afternoon due to an earlier rain-out, he hit a two-out ninth-inning home run off the Expos' Steve Rogers that proved to be the difference in a 2–1 Dodgers victory. Monday's home run dashed what turned out to be the Expos' only chance at a pennant in their 36-year history in the National League representing Montreal. Even today, heartbroken Expos fans refer to the fifth game of the NLCS as "Blue Monday." Los Angeles went on to win the 1981 World Series, defeating the New York Yankees 4 games to 2.