The first opening night game is held in St. Louis. The Cardinals, behind a complete game by Gerry Staley and home runs from Red Schoendienst and Stan Musial, beat the Pirates, 4 – 2, at Sportsman’s Park.

This Day In Baseball

On April 18, 1950 — The first opening night game is held in St. Louis. The Cardinals, behind a complete game by Gerry Staley and home runs from Red Schoendienst and Stan Musial, beat the Pirates, 4 – 2, at Sportsman’s Park.

Source
Baseball Reference April 18