Mike Schmidt homers in his first three times up for the Phillies, to give him a major league record-tying four straight over two games. Schmidt flies to the warning track in his next at bat, and the Phils lose, 8 – 6 to the Giants. Schmidt will hit three more home runs in the next three games to tie the National League record of seven home runs in five games.

On July 7, 1979 Mike Schmidt homers in his first three times up for the Phillies, to give him a major league record-tying four straight over two games. Schmidt flies to the warning track in his next at bat, and the Phils lose, 8 – 6 to the Giants. Schmidt will hit three more home runs in the next three games to tie the National League record of seven home runs in five games.

Source:
Baseball Reference July 7