Adams raked the two-bagger in the eighth inning of the Cardinals' victory on Friday at Busch Stadium in St. Louis.
The Cardinals and Giants were tied at 3-3 after seven innings before putting together a two-out rally. Jedd Gyorko began the eighth inning with a strikeout, before Yadier Molina grounded out to first base. Giants reliever Mark Melancon then walked Harrison Bader before allowing a single to Yairo Munoz.
San Francisco called on the bullpen once again, yanking Melancon for Tony Watson. Then Adams stepped up to the plate. He took two consecutive balls before fouling off Watson's third offering of the exchange. Watson then gassed in a 94-mph slider, which Adams sent to left field, bringing in the Cardinals' two baserunners and snatching a two-run lead.
Marcell Ozuna started the scoring on the night, bringing in Matt Carpenter on a first inning RBI single. Chris Shaw took a walk in the top of the third inning as the bases were loaded to tie the game for the Giants.
The Cardinals took another lead on Kolton Wong's RBI single in the fifth frame. Wong plated Jedd Gyorko with another RBI single in the sixth inning, giving the Cardinals a 3-1 edge.
Adams smacked his go-ahead double in the bottom of the next frame and the Cardinals pitcher Carlos Martinez closed out the Giants by striking out two of the final four batters.
"These kinds of wins are team wins," Adams told reporters. "We're taking care of business. We're not relying on anyone else to help us out. We're in a good spot, but we have to keep playing and keep taking care of it for ourselves."
The Cardinals and Giants take the field for the second game of the three-game series at 1:05 p.m. on Sunday in St. Louis.