The 1987 season saw rivalry at the end of the season, as on September 29, Yankees' first baseman Don Mattingly set an MLB record by hitting his sixth grand slam home-run of the season against the Red Sox. The competitiveness of the teams continued the following year. Co-captains Ron Guidry and Willie Randolph had led the Yankees to first place two weeks after the All-Star break. On July 28, the Yankees fell out of first place, and the Red Sox won their second division title in three years. Boston went on to face the Oakland Athletics in the 1988 American League Championship Series, but would end up getting swept.