sep 29, 1987 - Mattingly sets Major-League record with 6 Grand Slams in a Season
Description:
Mattingly clubbed all six of his slams saving three of them for the home crowd at Yankee Stadium. He did his damage early, clubbing all his slams before the fifth inning, and hit them in bunches: home runs 3 and 4 came within a week of each other in July, and number 5 and 6 were hit within five days of each other at the end of September. Mattingly's record-breaker came off Red Sox pitcher Bruce Hurst