SAN FRANCISCO -- Manager Gabe Kapler has consistently stressed the importance of staying even-keeled through the highs and lows of a Major League season. That message took on greater importance in recent days, when nothing seemed to be going right for the Giants as they scuffled through a five-game losing streak, their longest skid since August 2020.

With the Giants hosting Buster Posey Day at Oracle Park on Saturday, Kapler felt it was an opportune moment for the club to embrace the steadiness that the seven-time All-Star brought behind the plate over his 12-year run in San Francisco.

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“I don’t think there’s anybody that embodies that or exemplifies it better than Buster,” Kapler said before the game. “He’s incredibly calm and even. It doesn’t mean that you’re not working really hard, that you’re not process-driven. Buster was, and we will continue to be. But I’ll say that I think he’s a great example for us. A really appropriate mindset on Buster’s day.”

Perhaps inspired by Posey, the Giants subsequently snapped out of their offensive funk in emphatic fashion, crushing three home runs -- including a first-inning grand slam by Wilmer Flores -- and working eight walks to roll to a 13-7 win over the Cardinals on Saturday afternoon.

Mauricio Dubón and Darin Ruf, who have both endured slow starts at the plate, also delivered a pair of two-run shots -- their first homers of the year -- as the Giants erupted for eight runs against St. Louis left-hander Steven Matz over the first two innings. Flores added a sacrifice fly and a bases-loaded walk to finish with six RBIs, matching his career high.

“Teams go through little skids like that, and ours happened at the beginning of the year,” Dubón said. “It’s part of the game. We didn’t panic. We just kept playing the game. Good things are going to come.”

San Francisco had been outscored by a 51-23 margin while dropping seven of its previous eight games, but it received a significant boost with the return of first baseman Brandon Belt, who was activated off the COVID-19 injured list on Saturday after missing seven games.

Belt drew three walks in his first game back, but he experienced another bad break in the eighth, when he grimaced after taking a swing against Cardinals reliever Kodi Whitley and departed the game with head athletic trainer Dave Groeschner. Kapler said Belt experienced neck stiffness and is day to day.

While Belt’s return proved short-lived, he still made his impact felt on Saturday, helping to set the table for the Giants’ rallies in each of the first two innings. His first walk loaded the bases with one out for Flores, who followed with the fifth grand slam of his career. Flores drove a 2-2 sinker from Matz -- his former Mets teammate -- out to left field to put the Giants ahead, 4-1.

“Flo’s at-bat was huge,” Ruf said. “The offense needed an at-bat like that to get us going. For Flo to step up and hit a grand slam there was pretty awesome.”

Dubón entered Saturday batting .138 over 15 games this season, but he started at shortstop to give Brandon Crawford a day off against Matz. He made the most of the opportunity, smoking a 406-foot blast out to straightaway center field to kick off a four-run rally in the second.

Belt then drew another walk to set up Ruf’s homer, which traveled a projected 383 feet out to left-center field and stretched the Giants’ lead to 8-3. Like Dubón, Ruf had been making hard contact without much to show for it, batting only .188 over his first 26 games of the year.

“That ball that Mauricio hit was a bullet, and it was big for his confidence level,” Kapler said. “And obviously, Darin, he needed that. We all needed that.”

The Cardinals pulled within two on Dylan Carlson’s three-run shot in the seventh, but the Giants kept the pressure on, padding their lead behind Thairo Estrada’s RBI double in the seventh and a three-spot in the eighth.

Flores, who came up to the plate with the bases loaded three times, had a chance to add another slam after working a 3-2 count against Whitley in the eighth, but he took ball four to force in a run instead.

“I was thinking about it, like, ‘It could be cool,’” Flores said. “But I was just staying simple. Every time I think big, nothing good happens.”

The Giants’ offensive outburst obscured another uneven outing from right-hander Logan Webb, who allowed four runs on eight hits over five innings. After giving up two runs over 14 innings in his first two starts of the year, Webb has now surrendered 13 runs over 21 1/3 innings in his last four outings, bumping his ERA to 3.82 on the season.

“I don’t think this was Logan’s best performance,” Kapler said. “He got through it. I still think there’s a confidence level. There’s just a feel to the game that he has when he’s on, when his stuff has really good finish and when he’s locating really well. You can see just a little bit of the body language come out today where he’s frustrated. I think it was a frustrating performance for him. Good portions of the outing, but for the most part, I think there’s better in there.”