Pujols hit a two-run homer in the second inning, connecting as a pinch hitter for Justin Turner, who exited with left groin discomfort.
Pujols admired the 418-foot drive for a bit, then had a jubilant celebration with teammates in the dugout. It was the third pinch-hit home run of Pujols' career, the 14th home run of the season -- ninth in a Dodgers uniform -- and 676th in his storied career.
"It's not the first home run I've hit against the Angels," Pujols said. "To me, I'm just glad to be able to contribute to the ballclub and help win the series. I didn't put too much thought into it. It can be looked at a different way since it's a former team, but I don't look at it like that."
The 41-year-old Pujols connected off rookie Reid Detmers and gave the Dodgers a 5-0 lead.
Pujols chatted with his former teammates before the series started, then he said it was all about winning games.
"It's the first time I've seen some of these guys since I got released," Pujols said. "I still have a great relationship with 95% of those guys."
Cody Bellinger, the former National League MVP who has struggled mightily this season, homered for the second straight game, helping the World Series champions take two of three at Dodger Stadium in the Freeway Series.
But the day belonged to Pujols.
"It was great for him and to be ready when called upon since he wasn't in [the starting lineup] today," Dodgers manager Dave Roberts said. "Player comes in the game. He's five hitters away, takes an at-bat and hits a homer. I tip my cap. As far as hitting against a former team, he's happy to help the Dodgers win a ballgame."