On August 6, 1982 — Jack Clark and Reggie Smith both homer twice in San Francisco’s 7 – 6 win over Houston. The Giants trail, 6 – 4, in the 9th inning before Clark and Smith hit back-to-back home runs to send the game into extra innings.

Source:
Baseball Reference August 6
National Pastime
Retro Sheet
Hall of Fame
SABR Games Project
Replay The Game