John Franco of the New York Mets becomes the first left-handed pitcher to reach the 300-save plateau with a scoreless 9th inning in a 3 – 2 Mets win over the Expos at Shea Stadium.

This Day In Baseball

On April 22, 1996 — John Franco of the New York Mets becomes the first left-handed pitcher to reach the 300-save plateau with a scoreless 9th inning in a 3 – 2 Mets win over the Expos at Shea Stadium.

Source
Baseball Reference April 22