SAN FRANCISCO -- Last week, the Giants had no answers for D-backs right-hander Merrill Kelly.

Kelly spun eight scoreless innings at Chase Field on Thursday before Arizona’s bullpen imploded in the top of the ninth inning, allowing the Giants to erase a four-run deficit and rally for a dramatic win in 10 innings.

The Giants drew another matchup with Kelly on Wednesday night, but they had an easier time solving him this time around. Buster Posey, LaMonte Wade Jr., Brandon Crawford and Alex Dickerson each homered to power a 7-2 win over the D-backs, clinching a sweep of this two-game mini series at Oracle Park.

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San Francisco scored in each of the first four innings against Kelly, who was chased after allowing five runs on 11 hits over five innings. The Giants improved to 14-2 against Arizona this season and 73-41 overall, the best record in the Majors.

“I think we did a better job of picking good pitches to hit,” Crawford said. “[Kelly’s] done a good job against us for the most part all year. This was the fifth or sixth time I think we’ve faced him this year. I think we did a good job of picking good pitches to hit. We put some good swings on the ball, and we were able to score some runs.”

Kevin Gausman again struggled to find a consistent feel for his devastating splitter in his first start since returning from the paternity list on Sunday, but he managed to hold the last-place D-backs to two runs (one earned) on four hits and four walks over five innings.

The 30-year-old right-hander also helped his cause by going 2-for-2 with a go-ahead single, collecting his first career multihit game and lifting his batting average to .216 (8-for-37) on the season.

“Anything I do at the plate is kind of a bonus, but being able to contribute every once in a while is definitely nice,” Gausman said. “To be honest, I’m just up there trying to make contact and not look stupid.”

Gausman stepped up to the plate with runners on second and third and no outs in the second inning and beat Arizona’s drawn-in infield by bouncing a single up the middle to knock in Mike Yastrzemski from third and give the Giants a 2-1 lead.

Posey tacked on another run in the third, driving a first-pitch fastball from Kelly over the right-field arcade for his 15th home run of the season and his second in as many days. The opposite-field shot extended Posey’s on-base streak to a career-high nine consecutive plate appearances, though the impressive stretch came to an end when he popped out in his third at-bat of the night in the fifth.

“I think a lot of that has to do with the work that Buster does on a regular basis to keep his body strong,” manager Gabe Kapler said. “It’s the mechanics, it’s the preparation and it’s the health and explosiveness that’s leading to the success.”

Gausman added another single in the fourth to set up Wade’s two-run blast to center field, which deflected off Ketel Marte’s glove and went over the right-center-field wall to extend the Giants’ lead to 5-2. Marte couldn’t hide his frustration after narrowly missing the ball, making a throwing motion that suggested he had a strong urge to hurl his glove at the wall.

“Just watching it, I was just trying not to trip on second, first off,” Gausman said. “Then I thought he was going to rob it. I didn’t know if he caught it or not, but then the way he reacted, you could tell he didn’t catch it.”

Crawford joined the homer barrage with a solo shot off D-backs reliever Brett de Geus in the seventh, sending a misplaced sinker over the left-center-field wall for his 19th homer of the year, which tied Kris Bryant for the team lead. Dickerson capped the offensive output with a pinch-hit home run off Tyler Clippard that sailed into McCovey Cove in the eighth.

It was the first career splash hit for Dickerson, who became the sixth different Giant to accomplish the feat this year.

The Giants now lead the Majors with 174 homers this season, 56 of which have come from players age 34 and older.

“I think the mindset’s changed a little bit from an offensive standpoint,” Crawford said. “A few extra balls are probably getting out because of the fence changes, my last one included. We’re starting to get used to it. We’ve hit a lot this year, but it’s always fun to watch.”

The strength of the Giants’ offense, which received a major boost following the arrival of Bryant and the return of Tommy La Stella and Brandon Belt, has helped disguise some of the recent shortcomings of the starting rotation, which has had a harder time delivering quality starts in the second half.

Anthony DeSclafani and Johnny Cueto are currently on the injured list, and Gausman is still working to recapture the dominant form that earned him his first career All-Star selection last month. Gausman had his splitter working in the first inning, when he struck out the side on 14 pitches, but his control of that pitch then began to waver, forcing him to grind through the rest of his outing.

“That was kind of the story of my outing,” Gausman said. “Early on it was really good. I just lost the feel for it at times. It’s been pretty frustrating as of late.”