Davey Johnson’s ninth-inning bases-loaded home run off Terry Forster gives the Phillies a 5-1 walk-off victory over Los Angeles at Veterans Stadium. The 35 year-old second baseman is the first major leaguer to pinch-hit two grand slams in one season.

This Day In Baseball

On June 3, 1978 — Davey Johnson’s ninth-inning bases-loaded home run off Terry Forster gives the Phillies a 5-1 walk-off victory over Los Angeles at Veterans Stadium. The 35 year-old second baseman is the first major leaguer to pinch-hit two grand slams in one season.

Source
Baseball Reference June 3