Edgar Martinez hits three home runs, tying a major league record with five homers in two games, to give the Seattle Mariners a 10 – 1 victory over the Minnesota Twins. Martinez homered twice in the opener of the series.

This Day In Baseball

On May 18, 1999 — Edgar Martinez hits three home runs, tying a major league record with five homers in two games, to give the Seattle Mariners a 10 – 1 victory over the Minnesota Twins. Martinez homered twice in the opener of the series.

Source:
Baseball Reference May 18