"He's kind of doing everything for us," said Giants reliever Jeremy Affeldt, having watched his catcher drill a pair of hits, score a run and drive in another, while controlling the Dodgers' running game by gunning down three of four intended base thieves.
It didn't end well for Posey and his posse, the Dodgers rallying for runs in the eighth and ninth to move within 4 1/2 games of the first-place Giants in the NL West. But this did nothing to diminish one of the inspiring stories of the season, this remarkable performance by a great young player.
Posey has come all the way back to his 2010 World Series championship form following the horrific home-plate collision 16 months ago that ended his 2011 season, a complex surgery required to repair his shattered left ankle.
Posey is hitting .325, third in the league, with .524 slugging and .402 on-base percentages. His offensive WAR is second in the NL to that of McCutchen, who doesn't shoulder the catcher's responsibilities and burdens. Posey has caught 100 games and 863 innings, catching an occasional blow with 22 appearances at first base.
"To miss all the time he did and put together a year like this is impressive," said Giants manager Bruce Bochy, a former catcher who fully grasps the job's many physical and mental demands. "It shows you the gifts and talents this guy has."
It seemed inevitable that Adrian Gonzalez and Hanley Ramirez would break out for the struggling Dodgers, and it happened at AT&T Park at Affeldt's expense in the aftermath of an absorbing duel between the Giants' Matt Cain and Dodgers southpaw Chris Capuano.
Gonzalez, stung by Friday night's loss, came out with a commitment to aggression and drove Affeldt's first-pitch curveball leading off the ninth to the right-center gap -- his first triple of the season.
When Hanley Ramirez doubled him home and Brandon League subdued the Giants in the bottom of the ninth, the Dodgers had shaved the Giants' division lead back to 4 1/2 games while holding their place in a wild NL Wild Card chase.
"Any time you don't win the game it's frustrating," Posey said, "regardless of your performance."
No one was as frustrated as Cain. On a full count to pinch-hitter Bobby Abreu with one out in the eighth and pinch-runner Alex Castellanos on third base, Cain unleashed a changeup that danced away from Posey's grasp. Castellanos carried home the tying run.
"A lot of times it'll dive away from a lefty," Posey said of the wild pitch, "and that one kind of came across."
Juan Rivera had opened the inning with a double, just beyond Hunter Pence's grasp in the right field corner, moving up on A.J. Ellis' bunt.
A less disciplined hitter than Abreu could not have resisted a 2-2 Cain curveball that dipped just below the knees.
"That was the pitch I wanted," Cain said. Then came the one that refused to behave.
"It was supposed to be a changeup," Cain said, "but it cut the opposite way of where it was supposed to go."
Affeldt had no complaint with his curveball that Gonzalez drilled to the deepest area of a huge park.
"He's got a big bat, and he kind of buckled," Affeldt said. "You don't expect him to swing at it. It was a good pitch to a great hitter, one of the highest-paid players in the game -- and he did what he's paid to do.
"But, seriously, you swung at that pitch? And hit it in the one part of the park I don't want you to hit it?"
Earlier, it was Posey pounding Capuano. With Marco Scutaro (double) and Pablo Sandoval (single) at the corners in the first, Posey slashed a line drive off the glove of third baseman Luis Cruz for a 1-0 lead.
Capuano manufactured his own tying run in the sixth. After a one-out single in the sixth, he raced to third -- pitchers aren't supposed to do this -- on Mark Ellis' single to center and dashed home on Shane Victorino's sacrifice fly.
Posey, leading off the seventh, lashed a double down the left-field line. Brandon Belt's bullet off Capuano's glove cashed in Posey from third, the pitcher again using his athleticism to get an out and control damage.
The Dodgers pitched around Posey in the eighth, walking him to set up Pence with two on. Ronald Belisario struck out Pence and claimed the win courtesy of League's save when Gonzalez and Ramirez delivered.
Posey is too deeply in the thick of it to fully appreciate what he's done.
"It'll be easier to reflect on it once the season is over," he said. "You want to finish strong, and hopefully you can reflect on a good season, getting in the playoffs."
And, perhaps, repeating some magical recent history.