SAN FRANCISCO — Out of nowhere came the fan, a large man in an old-school Barry Bonds Pirates jersey entering Gregory Polanco’s space at the right-field wall.

The fan and the outfielder both reached, and neither came up with the ball. Pittsburgh manager Clint Hurdle requested a replay review and, after 2 minutes, 17 seconds, Polanco was credited with the putout in the eighth inning of a 4-3 victory against the San Francisco Giants on Monday night.

“He hit me all over,” Polanco said, gesturing to his hand and the left side of his face. “He said, `I’m very sorry.’ I said, `It’s OK, man.’ He’s trying to catch the ball, too. He wants the ball. It was strange. He was right there and I didn’t see him before.”

Gerrit Cole struck out nine in seven innings to win his third straight start and take a share of the majors’ wins lead, while Neil Walker hit a tiebreaking two-run double in the fifth after two called strikeouts.

Andrew McCutchen had two likely hits stolen by great plays in the outfield as he settled instead for sacrifice flies against Ryan Vogelsong (4-3).

Cole (8-2) struck out the side in order in the fourth, then worked a 1-2-3 fifth before loading the bases with no outs in the sixth. He got out of it with a strikeout of Brandon Belt and inducing Brandon Crawford’s inning-ending double play.

“To come back and have command of all his pitches and stuff through the seventh, it was a very impressive performance from start to finish,” Hurdle said.

Belt’s two-run, two-out double in the first put San Francisco ahead early in a rematch of the NL one-game wild card won 8-0 by the eventual champion Giants last October at PNC Park.

The Pirates-clad fan was removed from the stands after he leaned over the low fence and prevented Polanco from catching Buster Posey’s ball.

“How about the irony that the game has and the guy had a Pirate jersey on. I don’t know if he thought he could make the catch and hand it to Gregory or maybe help Gregory,” Hurdle said. “It was the right call. ... There’s some depth to that guy out there.”

Hurdle tweaked his lineup to use lefty hitters high in the order with Polanco batting second and Walker cleanup. Walker came in 7 for 16 against Vogelsong and delivered in the fifth, leading Pittsburgh to its ninth win in 11 games.

Center fielder Angel Pagan made a running, diving backhanded catch on McCutchen’s third-inning drive. Pagan hopped up and quickly released the throw. Right fielder Hunter Pence robbed McCutchen in the fifth, prompting the slugger to raise his hands in a signal of disbelief.

“You kind of get used to seeing it. Pagan made an unbelievable play, Pence made an unbelievable play,” Vogelsong said.

Cole, making his first career start in San Francisco, allowed five hits and no earned runs to improve to 3-0 against the Giants. The right-hander is 12-2 with 120 strikeouts in 16 starts since Sept. 7 — the most wins in the majors in that stretch.

Nori Aoki scored on Pence’s groundout in the eighth, then Mark Melancon finished for his 14th save.

The Giants, coming off a 21-9 May, have their first three-game losing streak since dropping a season-high eight straight from April 10-17.

Vogelsong lost for the first time in six starts since a defeat to Los Angeles on April 29 at Dodger Stadium, and the Giants had won each of the right-hander’s last five and six of seven.

He went 4-0 with a 1.14 ERA in five May starts.

Pittsburgh took two of three games in both series the teams played in 2014. The Giants have lost 11 of 16 overall to the Pirates.