New spot in Dodgers order goes a long way for Joc Pederson

When explaining why Joc Pederson was made the Dodgers’ new leadoff hitter, Don Mattingly pointed to the rookie’s on-base percentage. He talked about how Pederson stole 30 bases last season in the minor leagues.

The manager barely mentioned another part of Pederson’s game that could be useful when batting first: his power.

Pederson used that power to establish a night-long theme for the Dodgers in his first at-bat Wednesday night, as he redirected a first-inning offering from Ryan Vogelsong over the right-field wall at Dodger Stadium. The long ball was the first of four for the Dodgers in their 7-3 victory over the San Francisco Giants, as Adrian Gonzalez, Andre Ethier and Jimmy Rollins also homered.

By claiming two wins in the three-game series against the Giants, the first-place Dodgers (13-8) extended their lead over the second-place Colorado Rockies to two games. The Dodgers are now 4 1/2 games ahead of the last-place Giants, who swept them last week in San Francisco.

Pederson batted eighth in 14 of his previous 18 starts. He batted seventh in the other four games.

“There have been some injuries. You kind of have to adapt,” the rookie said. “I was trying to get something going.”

Said Mattingly: “Really, the eighth spot is designed to allow him to not feel any offensive pressure at all, just be able to play and do his thing. I think we’re probably comfortable after a month that this is not going to change anything.”

The left-handed-hitting Pederson entered the game Wednesday with an on-base percentage of .458, which ranked third in the National League.

“Obviously, he’s handled that eighth spot,” Mattingly said. “It’s really a tough spot for a young player, with that pitcher behind you. We’re not asking him to do anything differently. I know everybody makes a big deal out of lineup changes and things, but you’re not doing anything differently.”

Shortstop Jimmy Rollins, who batted leadoff in 18 of the Dodgers’ previous 20 games, was batting only .182.

With Yasiel Puig and Carl Crawford landing on the disabled list in recent days, the Dodgers had an opportunity to reconfigure their lineup, which they did.

Rollins, a switch-hitter, was dropped to second.

Not wanting to bundle too many left-handed hitters near the top of the order, Mattingly moved Gonzalez from third to cleanup. Gonzalez traded places in the lineup with Howie Kendrick, a right-handed hitter.

Catcher Yasmani Grandal, the team’s regular No. 5 hitter, fell back into the seventh spot. Grandal started the day with a .196 average.

“If he can just simplify it, he’s going to be fine,” Mattingly said of the catcher. “I feel like he’s trying really hard.”

The home-run parade that ensued probably was more of reflection of Vogelsong than it was of lineup.

Now four years removed from his All-Star season, Vogelsong came into the game with a 7.71 earned-run average. In 16 1/3 innings, he had given up four home runs.

Vogelsong’s second pitch to Pederson on Wednesday night turned into Pederson’s fourth homer of the season.

Three batters later, Gonzalez belted his seventh home run of the season to move the Dodgers in front, 2-1. The first-inning thumping continued with a two-run home run by Ethier that increased the Dodgers’ lead to 4-1.

Rollins hit a leadoff home run of his own in the third inning. Kendrick scored later in the inning on a sacrifice fly by Scott Van Slyke, increasing the margin to 6-1.

The inning was the last pitched by Vogelsong, who was charged with six runs and five hits. The 37-year-old right-hander departed the game with an ERA of 9.31.

Dodgers starting pitcher Zack Greinke, who limited the Giants to three runs and seven hits over six innings, improved his record to 4-0.

dylan.hernandez@latimes.com

Twitter: @dylanohernandez