LOS ANGELES -- The Los Angeles Dodgers ended their drought against the San Francisco Giants, but that was merely water down the drain Friday night.

Catcher Buster Posey hit a grand slam, and the Giants continued their dominance of the rival Dodgers, earning a 9-5 victory at Dodger Stadium.

"He's our clean-up hitter, he's an impact player," Giants manager Bruce Bochy said. "You want the right guy up there with the bases loaded. He got a mistake, and took advantage of it."

Shortstop Brandon Crawford and third baseman Matt Duffy each drove in a pair of runs as the Giants (37-32) defeated the Dodgers (38-30) for the eighth time in 10 meetings this season. The Giants also cut the first-place Dodgers' cushion to 1 1/2 games in the National League West.

"I can't say something stands out with the matchup," Bochy said. "We have played very good ball against them. Pitched very well and we've gotten timely hits, played good defense, and that's what wins games for you."

Posey had no answer for the Giants' success, either.

"Nothing to really put the finger on. Just we've been playing sound baseball against them," Posey said.

Giants starter Chris Heston (7-5) gave up three runs on seven hits in 5 2/3 innings, striking out one and walking none. Posey's blast put him at ease and allowed him to pitch, Heston said.

"Anytime you're scoring runs and you're out there, it definitely helps you relax a little bit," said Heston, who made his first career start against the Dodgers and became the first San Francisco rookie to win at Dodger Stadium since Madison Bumgarner did so on July 19, 2010. "I was trying to throw as many strikes as possible and let the defense work. They made a lot of plays tonight."

Crawford hit an RBI double in the sixth for a 5-3 Giants' lead, but Dodgers center fielder Joc Pederson prevented the Giants from scoring more in the inning by making a diving grab of a line drive by right fielder Gregor Blanco with runners at first and second.

However, a two-run single by Duffy in the seventh keyed a four-run surge by the Giants (37-32) and helped them pull away.

Dodgers right-hander Mike Bolsinger surrendered five runs on eight hits with six strikeouts and three walks in 5 1/3 innings. It was the most runs allowed by Bolsinger (4-2) this season.

Third baseman Justin Turner homered for the Dodgers.

The Dodgers scored again San Francisco for the first time in 32 1/3 innings. Catcher Yasmani Grandal's RBI single with one out in the second gave the Dodgers a 1-0 lead. It was the longest stretch for the Dodgers, who were shut out in three straight losses in San Francisco May 19-21, since the Pittsburgh Pirates blanked them for 33 consecutive innings over two seasons in 1967 and 1968.

Posey wiped out the deficit with one swing, drilling a curveball from Bolsinger into the Dodgers bullpen in left for a grand slam and a 4-1 Giants' advantage with two outs in the third. It was the 10th home run of the season for Posey and his third career slam.

"I got a pitch that stayed up," said Posey, who went 3-for-4 with four RBIs and also recorded his first stolen base of the season. "Really just trying to stay small there, especially with two strikes, and not trying to do too much. I feel like you can get in trouble thinking home run. It can get a little big."

Bolsinger lost for the first time at home this season.

"There's a reason why (Posey) is one of the best hitters in the league," Bolsinger said. "He's definitely a tough out, always, in any situation."

Turner smoked a run-scoring double past left fielder Nori Aoki to score Pederson, who also doubled, in the third. First baseman Adrian Gonzalez followed with a single to bring home Turner to pull the Dodgers within 4-3, but the Giants answered by scoring five straight runs.

NOTES: San Francisco OF Gregor Blanco was activated Friday from the seven-day disabled list after sitting out the previous nine games with concussion-like symptoms. Blanco, who went 2-for-4 with an RBI, started in right field, where he will primarily play until the return of injured OF Hunter Pence, who is on the disabled list with left-wrist tendinitis. The Giants optioned OF Jarrett Parker to Triple-A Sacramento. ... Injured Dodgers RHP Pedro Baez, RHP Brandon League and RHP Joel Peralta were scheduled to pitch in rehab assignments Friday night with Triple-A Oklahoma City. ... Giants broadcaster and former major leaguer Duane Kuiper celebrated his 65th birthday. ... Giants RHP Tim Hudson (4-6, 4.65 ERA) will face Dodgers RHP Carlos Frias (4-4, 4.14 ERA) on Saturday.