LOS ANGELES (AP) — Buster Posey and Wilmer Flores hit back-to-back homers in the first inning, Thairo Estrada had a key double in the seventh and the San Francisco Giants defeated the Los Angeles Dodgers 7-2 in the opener of a pivotal four-game series between the NL West rivals.

Posey had two hits and drove in two runs in his first game back after he missed two weeks due to a bruised left thumb. Estrada — who is taking over at shortstop after All-Star Brandon Crawford was placed on the injured list due to a strained oblique — came through with a two-run double in the seventh inning as the Giants broke open a close game by scoring four times.

What You Need To Know

  • The Dodgers lost to the Giants 7-2 Monday night in LA

  • Max Muncy and Justin Turner homered for Los Angeles, which was held to four hits

  • Tony Gonsolin yielded three runs on five hits in 3 1/3 innings with four walks and three strikeouts. Only 39 of his 80 pitches were strikes

  • Up next: San Francisco LHP Alex Wood (8-3, 3.67 ERA) is 2-0 with a 2.25 ERA this month. Los Angeles had not announced a starter

Max Muncy and Justin Turner homered for Los Angeles, which was held to four hits. San Francisco pitchers had retired 11 straight Dodgers until AJ Pollock led off the ninth with a single.

With the win, the Giants expanded their lead to two games over the defending World Series champion Dodgers. San Francisco has been in first place since May 31.

Jarlín García (2-2), the third of six San Francisco pitchers, got the win by striking out two in 1 1/3 innings.

Posey didn't waste any time making his presence felt. With one out in the first, he took advantage of a hanging slider from Tony Gonsolin (1-1) on a full count and ripped it into the stands in left field for a two-run shot and his 13th of the season. Posey drove in LaMonte Wade Jr., who led off the game with a double into the right-field corner.

Two pitches after Posey's homer, Flores went deep to right to extend San Francisco's lead to 3-0. Along with it being Flores' 10th, it was the sixth time this season the Giants hit back-to-back home runs.

The Dodgers responded in the first with solo shots by Muncy and Turner. Muncy crushed Kevin Gausman's fastball down the right-field line on the first pitch of the at-bat for his eighth homer against the Giants this season. Muncy is the sixth Dodgers player, and first since Ron Cey in 1978, to go deep at least eight times against the Giants in one year.

Turner then brought the Dodgers to 3-2 with a drive into the center-field seats. It was the second time this month and seventh time this season the Dodgers went back-to-back.

San Francisco got breathing room in the seventh. Jason Vosler drove in Posey on a sacrifice fly with the bases loaded to make it 4-2. Estrada followed with a two-run double to left and came home when Austin Slater laced a double down the right-field line.

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Better late than never

According to Sportradar, this was the first time in the 2,526 regular-season games of the Giants vs. Dodgers rivalry that both teams hit back-to-back homers in the first inning.

For starters

Gausman went a season-low three innings, throwing 80 pitches. The right-hander allowed two runs on three hits but walked five with three strikeouts. He issued back-to-back walks to Muncy and Turner to load the bases in the second inning but got out of the jam with a strikeout to Will Smith.

Gonsolin yielded three runs on five hits in 3 1/3 innings with four walks and three strikeouts. Only 39 of his 80 pitches were strikes.

Trainer's room

Giants: 2B Tommy La Stella (left hamstring strain and right thumb) started hitting again. The plan is to have him back in rehab games toward the middle or end of this week.

Dodgers: INF Gavin Lux was placed on the 10-day injured list due to a left hamstring strain. OF Zach Reks was recalled from Triple-A Oklahoma City to fill the roster spot.

Up next

San Francisco LHP Alex Wood (8-3, 3.67 ERA) is 2-0 with a 2.25 ERA this month. Los Angeles had not announced a starter.