His stuff looked familiar even if they were trying to hit it instead of watching him close a game for San Francisco.
Wilson earned his second win since joining the Los Angeles Dodgers when Adrian Gonzalez singled home the decisive run in the 10th inning of a 3-2 victory Thursday night.
The loss ended last-place San Francisco's streak of four consecutive winning seasons.
Wilson (2-1) pitched against his former teammates for the first time since spending seven seasons in San Francisco, where he was part of two World Series championship teams. He tossed one scoreless inning of relief.
Giants catcher Buster Posey said it was fun facing a good pitcher like Wilson. Posey flied out to right field for the second out of the 10th.
"It's obviously different hitting him instead of catching him, but just looking at the velocity of the cutter and the fastball, it's pretty close to where he always is," Posey said.
Giants manager Bruce Bochy still appreciates what Wilson did in San Francisco, where "The Beard" was a three-time All-Star before an elbow injury ended his tenure with the Giants last year.
"He got it up there to about 94 (mph), used his sinker and slider, so it was similar to what he was throwing for us," Bochy said.
The Dodgers reduced their magic number to five for clinching their first NL West title since 2009. They won for the seventh time in eight games against the rival Giants, a stretch that began with a three-game home sweep June 24-26.
Carl Crawford opened the 10th with a single off Jeremy Affeldt (1-5). Pinch-hitter Nick Punto sacrificed Crawford to second before Gonzalez stroked a single into center field for the Dodgers' eighth walk-off win of the season.
Affeldt was activated from the disabled list before the game.
Gregor Blanco's RBI single off Dodgers closer Kenley Jansen tied the score 2-all in the ninth. Jansen allowed a leadoff single to Pablo Sandoval. He was replaced by pinch-runner Juan Perez, who stole second and advanced to third on a passed ball by catcher Tim Federowicz.
The Giants threatened in the eighth when they loaded the bases before Hunter Pence hit into an inning-ending double play.
San Francisco led 1-0 on Pence's home run leading off the second.
Dodgers starter Zack Greinke allowed one run and four hits in six innings. He struck out five and walked two in his second straight no-decision.
Giants starter Matt Cain gave up two runs — one earned — and six hits in seven innings. The right-hander struck out five and walked one in his second start since coming off the disabled list after missing 14 games with a bruised right forearm.
Los Angeles took a 2-1 lead with two outs in the seventh. Yasiel Puig doubled to deep left-center, scoring pinch-runner Dee Gordon, who came in after A.J. Ellis hit a leadoff single. Gordon stole second and was sacrificed to third by Mark Ellis.
The Dodgers tied it at 1 on a grounder by Mark Ellis in a messy second for the Giants that included a throwing error by Cain.
"He hit the ball a little harder than I thought he did and I thought I had to jump to catch it, so that kind of changes the timing a little bit," Cain said. "But that's not an excuse. That's a play that should be made."
Greinke reached on an infield single to third after Sandoval slipped fielding the ball.
NOTES: The Giants' 13-game errorless streak was snapped with Cain's miscue. ... Blanco's three hits tied a season high. ... The Giants felt to 8-10 in extra-inning games, including 1-4 on the road, and to 23-26 in one-run games. ... It was San Francisco's ninth walk-off loss of the season. ... Affeldt missed the previous 50 games with a left groin strain. ... Three of the four games in the series are sold out.