Playing as a visiting player at Busch Stadium for the first time in his career this weekend, Pujols took a 2-1 pitch from Cardinals starter Dakota Hudson over the left field wall. Pujols' 13th home run of the year gave the Angels their first run in Saturday's 4-2 loss and sent the crowd into a frenzy.
Pujols received a standing ovation as he rounded the bases and removed his helmet for a curtain call after returning to the visitors' dugout. The three-time MVP went 1-for-4 on Saturday.
The home run went a projected 408 feet, according to MLB Statcast.
Pujols hit 445 home runs in 11 seasons with the Cardinals, including 110 at the current Busch Stadium from 2006 to 2011. He hit 94 at the previous Busch Stadium from 2001 to 2005.
Los Angeles fell to 38-40 with their third-straight loss. The Angels are 4 1/2 games behind the Boston Red Sox for the American League's second Wild Card spot.