PITTSBURGH — Matt Chapman homered for the third straight game, this one a three-run drive during an eighth-inning rally, and the San Francisco Giants spoiled a solid start by Pittsburgh Pirates rookie Paul Skenes to surge to a 7-6 win on Thursday.

Chapman went deep off Hunter Stratton (1-1), and Brett Wisely delivered a go-ahead single off Aroldis Chapman five batters later as the Giants overcame a big deficit for the second time in less than 24 hours.

San Francisco trailed by five early in a 9-5 extra-inning victory on Wednesday. The Giants were down 6-2 through seven on Thursday before Chapman & Co. got going against Pittsburgh’s struggling bullpen as the Giants won consecutive games in which they trailed by at least four runs for the first time since 1998.

Skenes allowed one run on six hits with a walk and three strikeouts in six innings in his third major league start. He exited with the Pirates comfortably ahead before things fell apart.

Chapman, Wisely, Lamont Wade Jr. and Heliot Ramos had two hits apiece for the Giants, who won for just the fifth time in their last 13 road games. Luke Jackson (2-1) picked up the win by working the seventh. Tyler Rogers pitched the ninth for his first save this season.

The rally came after Skenes had long since exited following another impressive outing.

The 6-foot-6 right-hander struck out just three in his third major league start but expertly worked his way around traffic on the bases. The 21-year-old rookie allowed six hits (all singles) with a walk while lowering his ERA to 2.25.

It’s when Skenes left that things got dicey.

“Our bullpen has got to be better,” Pirates manager Derek Shelton said. “We had, what, a 5-1 lead yesterday, 6-2 lead today? We have to be better. … We have to win games like that.”