SAN FRANCISCO -- Three outs from a stinging series loss to the last-place San Francisco Giants, lightning struck the playoff-contending Milwaukee Brewers on Wednesday afternoon.

It hit them in the foot, adding to the pain.

Jarrett Parker's check-swing, two-run double broke a seventh-inning tie and sent the Giants to a 4-2 victory and series win over the Brewers, who might have lost slugger Travis Shaw in the process.

The star third baseman fouled a ball off his right foot in the ninth inning and, after drawing a walk, left the field with a serious limp moments later.

"We don't know," Brewers manager Craig Counsell said of the extent of the injury. "He'll get X-rays."

Left-hander Matt Moore pitched six strong innings before handing off the ball to the bullpen, helping the Giants win for a second time in the three-game series.

"I thought everybody did well," Moore said of the series win. "They have a good chance to get into the postseason. So for us to come in here and kind of ruin someone's day, it was something for us moving forward that we can build on as a club."

The loss dropped Milwaukee to 3-3 on its nine-game Western swing.

"We just didn't do enough today," Counsell lamented. "They pitched well and their bullpen did a nice job. We just couldn't push the runners across."

Pinch-hitter Denard Span's one-out double down the right field line against the Brewers' third pitcher, right-hander Jacob Barnes (3-4), got the decisive seventh inning rolling for the Giants.

After Gorkys Hernandez was hit by a pitch, Barnes struck out Kelby Tomlinson for the second out before jamming Parker with a fastball that the lefty hitter blooped just inside third base and into the Giants' bullpen, easily scoring Span and Hernandez with the difference-making runs.

"You hear good things happen to you when you put the ball in play, and he did," Giants manager Bruce Bochy noted. "I don't think that was the swing he was looking for on the first pitch, but that's a break for us. We'll take it."

Barnes came within one strike of retiring Hernandez before grazing his jersey with a fastball.

"Had a little bad luck there," Counsell said of Parker's hit. "The hit by pitch ended up hurting us."

Right-handers Hunter Strickland (3-3), Mark Melancon and Sam Dyson took it from there, limiting the Brewers to just one run on one hit over three innings to cap a 4-3 season-series win that was the Giants' fourth in a row against Milwaukee.

Aided by an insurance run produced by a Carlos Moncrief sacrifice fly in the bottom of the eighth inning, Dyson allowed a solo home run to pinch-hitter Stephen Vogt in the ninth before recording his 12th save.

Vogt's homer was his fifth of the season and the first of his career as a pinch hitter.

Hernandez had two doubles for the Giants, who totaled five doubles among their nine hits.

Tomlinson and Brandon Crawford also had two hits for San Francisco.

Domingo Santana collected a single and a double for the Brewers, who were seeking their first series win in San Francisco since 2010.

Both starting pitchers left with the game tied 1-1 after strong efforts that began with first-inning runs.

Moore allowed five hits, including doubles by Santana and Shaw that gave the Brewers a quick 1-0 advantage.

"It's about how you finish in this game," Bochy said of Moore's season, which began 3-12 before he's turned things around with three straight solid efforts. "We're all going to have our struggles, our hiccups, our bumps in the road, whatever. What's important is how you deal with it."

Moore walked two and struck out six.

The Giants got even against Brewers right-hander Matt Garza after loading the bases against him in the last of the first on a double by Hernandez, a single by Tomlinson and a walk to Parker.

Buster Posey tied the game with a sacrifice fly, after which Garza escaped further damage.

Garza allowed five hits in five innings. He walked two and struck out six.

"I was going into the game thinking: If Matt gives us 15 outs, we're in good shape," Counsell noted. "One run in five innings. I'll take that every single time. He did exactly what we asked him to do."

The Giants out-hit the Brewers 9-6.

NOTES: There were just 15 total runs scored in the series, the fewest in any Giants three-game series this season. Their previous low had been 16 against Washington on May 29-31. ... The Brewers and Tampa Bay Rays totaled just eight runs in a three-game series earlier this month. ... Giants RHP Sam Dyson's 12 saves since July 1 are tied for the most in the National League. ... Giants RF Hunter Pence (sore left hamstring) was held out of the starting lineup for the second straight day. ... Before the game, the Brewers claimed RHP Aaron Brooks off waivers from the Chicago Cubs. He was sent to Triple-A Colorado Springs. RHP Paolo Espino was designated for assignment to make room on the 40-man roster for Brooks. ... Both teams are off Thursday before starting road series on Friday, the Brewers in Los Angeles to face the Dodgers, and the Giants in Arizona to duel the Diamondbacks.