Posey accounted for all of the Giants' scoring. He lashed a two-run double to AT&T Park's 421-foot marker in the first inning off Pirates rookie sensation Jameson Taillon, who was charged with only one earned run in his previous two starts. Posey also singled and scored in the sixth inning off Taillon, who was duly impressed by his adversary.
Posey recorded both of his hits on curveballs.
"The first one had good break, had good depth. That's just a frickin' pro hitter staying inside the ball," Taillon said. "I did hang it, but it was still a sharp curveball. The last one, where he got the hit to right, that was a really good curveball. That dude's going to get his hits. He's one of the best in the game for a reason."
Posey's double represented San Francisco's lone hit in 11 at-bats with runners in scoring position.
Though Posey's back didn't bark at him during any of his four plate appearances, he revealed that he hyperextended his left elbow in his first at-bat. He emphasized this never bothered him, either.
After stroking his sixth-inning single, Posey appeared to labor around the bases after Brandon Crawford, the next batter, doubled to left-center field. Posey was forced to stop at third base, though he ultimately scored on Hunter Pence's groundout.
"Running wasn't great," Posey said, "but I got through it."
Posey also contributed defensively by throwing out Andrew McCutchen on an attempted steal of second base in the sixth inning.
"Catching actually feels good," Posey said. "I don't know if it's the positioning of where my back is. It's fine."
Giants manager Bruce Bochy said of Posey, who played the entire game, "He didn't complain of anything."
Nor did Posey express gloom after the Giants slipped into second place in the National League West with their 20th loss in 29 games since the All-Star break.
Asked if the Giants felt alarmed by the Dodgers' half-game lead in the division race, Posey said, "I think the alarm has been there for a while. I don't know if there's any more of a sense of alarm just because you're out of first. I kind of feel like we're beating a dead horse, but the only thing you can do is try to remain as positive as possible and hope that we get on track. We know that we can do that."
Posey realizes how he can further any improvement the Giants might make, beginning with Wednesday's series finale against Pittsburgh.
"I'm planning on playing," he said.
Chris Haft has covered the Giants since 2005, and for MLB.com since 2007. Follow him on Twitter at @sfgiantsbeat and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.