Wood allowed eight hits and one run in six innings in the 4-1 win Sunday at PNC Park. He pocketed six strikeouts and lowered his season ERA to 1.75.
The Giants pushed ahead 1-0 when Alex Dickerson grounded into a force out, and Mike Tauchman scored from third base in the top of the first inning.
Pirates left-fielder Ka'ai Tom tied the score with a sacrifice fly RBI in the bottom of the fourth inning. The Giants regained the lead when Evan Longoria scored on a wild pitch in the top of the sixth inning.
The Giants carried the narrow lead into the ninth inning. Tauchman took a walk to start the final frame. Giants right-fielder Mike Yastrzemski then stepped into the box to face Pirates relief pitcher David Bednar.
Yastrzemski took two consecutive pitches for balls. He swung and missed at a split fastball for strike one. The Giants outfielder hit the next pitch over the right-field fence for a 406-foot homer. The two-run shot traveled 101 mph off Yastrzemski's bat, according to Statcast.
Giants relief pitcher Tyler Rogers hit Tom with a pitch in the first exchange of the bottom of the inning. He retired the next three hitters in order to earn his fourth save of the season.
Giants catcher Buster Posey went 3 for 4 in the win. Infielder Mauricio Dubon recorded two hits in the victory. Pirates second baseman Adam Frazier and third baseman Erik Gonzalez recorded two hits apiece in the loss.
Pirates starter Mitch Keller allowed six hits and two runs in five innings to drop to 2-5 on the season.
The Giants (24-16) face the Cincinnati Reds at 6:40 p.m. EDT Monday at Great American Ball Park in Cincinnati. The Pirates (17-23) battle the St. Louis Cardinals at 7:45 p.m. EDT Tuesday at Busch Stadium in St. Louis, Mo.