Grand Slam Single
Robin Ventura, the next batter, drilled a 1-1 pitch over the right-centerfield wall for a grand slam, sending the Mets players and fans into a frenzy. Ventura was mobbed halfway between first and second base by his teammates. The official scorer awarded Ventura a single on the grand slam because he only touched first base.
Another instance of a Grand Slam Single:
July 9, 1970: Dalton Jones of the Detroit Tigers loses a grand slam against the Boston Red Sox when he passes teammate Don Wert on the base paths. Jones pinch hits for Jim Price and belts a 2-2 pitch from Vincente Romo into the RF upper deck for a grand slam. However, he passes Wert between first and second and is called out, ending up with a 3-RBI single.