SAN FRANCISCO -- Playing catch-up in a playoff chase and facing San Francisco Giants ace Madison Bumgarner, the St. Louis Cardinals elected to sit 15-, 18- and 19-homer hitters Sunday.

In the end, it was Bumgarner who had to be benched early.

Rookies Paul DeJong and Jose Martinez smacked back-to-back home runs off Bumgarner, and recent minor league call-up Harrison Bader added a solo shot to power the Cardinals to a 7-3 victory over the Giants.

Right-hander Luke Weaver struck out nine in seven strong innings as St. Louis took three of four in the series to claim the season set 4-3 from the Giants.

"I don't see it as a difficulty," Cardinals manager Mike Matheny said of the decision to sit Randal Grichuk, Matt Carpenter and Dexter Fowler and go with younger players. "I see it as a pleasure to get to decide which guys get an opportunity. It's a nice problem to have."

The win allowed St. Louis (69-67) to move within three games of the Colorado Rockies (72-64) in the race for the second National League wild card.

The day wasn't a total loss for Bumgarner (3-7), who allowed five runs and five hits in six innings. The slugging pitcher belted his third homer of the season, a solo shot off Weaver in the fifth inning that temporarily drew the Giants even at 2.

Bumgarner became the first pitcher since Earl Wilson of the Boston Red Sox and Detroit Tigers from 1964-68 to record three or more home runs in four straight seasons. The homer was the 17th of his career.

Bumgarner, however, was more concerned with his pitching.

"I don't think whether it's 30 degrees or 100 degrees, all the balls that got hit today, at least off of me, I don't think it would've had any kind of effect on them at all," Bumgarner said of another hot day by the San Francisco Bay.

"I'm obviously disappointed with my part. I didn't give us a chance to win today. I let that game to get away from me. I've got to find a way not to do that. I can't let that happen."

Bader's homer, his second of the series after being promoted from Triple-A Memphis on Friday, came with one out into the sixth inning and gave the Cardinals the lead for good.

Martinez and Yadier Molina had RBI doubles later in the inning, extending the advantage to 5-2.

"We have some depth on our bench," said Martinez, whose .440 average as a pinch hitter is the best in baseball among players with more than 13 such at-bats. "We had a lot of good at-bats today. (Bumgarner) made a couple of mistakes, and we took advantage of them."

The Cardinals added two insurance runs off the Giants' bullpen in the seventh, with Martinez contributing his second run-scoring double in as many innings.

He finished 3-for-5, including his fourth-inning homer of Bumgarner, his 11th of the season.

"I'm getting some chances," Martinez said of his 43rd start. "I'm just taking advantage of the opportunities."

DeJong's homer, his 21st of the year, came three pitches earlier, triggering the back-to-back that flipped a 1-0 San Francisco lead.

The consecutive homers were the Cardinals' seventh of the season.

Weaver (4-1), who had struck out 10 batters in each of his previous two starts, left for a pinch hitter in the eighth inning. No rookie pitcher has more than two 10-strikeout games this season.

He allowed two runs on four hits and two walks Sunday en route to his fourth win in five starts this season.

Bumgarner, pitching three days after having to be scratched from a start because of an illness, walked two and struck out five in his six innings.

Giants pitchers allowed eight hits and were spared three others by sensational catches by center fielder Gorkys Hernandez.

One of Gorkys Hernandez's grabs -- a running, leaping catch above the center field fence on a first-inning blast by Tommy Pham -- prevented what would have been a fourth homer off Bumgarner.

Matheny called the denial on Pham "one of the best catches I've ever seen."

Giants manager Bruce Bochy elaborated.

"Gorkys had quite a game, didn't he? I'm trying to add up the runs he saved us," Bochy said. "The second hitter (Pham), I thought that ball was out of the park. What a great catch.

"That's one of the best defensive games I've seen one player have with all the plays he made. It's exciting to watch those kinds of plays."

Martinez drove in three runs with his three hits and Bader had two RBIs with two hits for the Cardinals, who had three doubles and three homers among their eight hits.

Backup catcher Tim Federowicz hit his first home run of the season for the Giants. Mac Williamson, recalled from Triple-A Sacramento before the game, added two doubles for San Francisco, which had won or tied its previous six home series.

NOTES: The three home runs allowed by Giants LHP Madison Bumgarner tied a career high, set five times previously. ... Cardinals OF Harrison Bader's first two major league home runs have come off Giants RHP Johnny Cueto and Bumgarner. ... The Cardinals sat out CF Dexter Fowler (bruised left hip), who got banged up sliding into second base in Saturday's game. The injury is not considered serious. ... Cardinals RHP Sandy Alcantara pitched to five batters in his major league debut in the eighth inning and recorded several firsts, including strikeout (C/1B Buster Posey) and home run allowed (C Tim Federowicz). ... When Giants LHP Matt Moore entered the game as a reliever in the eighth inning, it scratched him from his tentatively scheduled start Monday at Colorado. RHP Chris Stratton will take his place. ... Before the game, the Giants recalled INF Orlando Calixte and LF Mac Williamson from Triple-A Sacramento.