The 42-year-old Brodeur started Thursday night against the Nashville Predators, joining St. Louis after Brian Elliott was sidelined by a knee injury.
He made a fine save in close against Colin Wilson less than a minute into his debut.
The Blues signed Brodeur to a one-year contract on Tuesday, though he hooked up with St. Louis last week and practiced fully on Monday.
Brodeur played 21 seasons for the Devils and won three Stanley Cup titles. The four-time Vezina Trophy winner looked to resume his career since the off-season after going 19-14-6 with a 2.51 goals-against average, .901 save percentage and three shutouts in 39 games last season.
Brodeur is 688-394-176 and holds most major regular-season goalie records including games (1,259).