One inning later, the game was over, as Brandon Crawford lined a single into center field and the Giants posted a 3-2 victory over the Padres before a sold-out crowd of 42,559 at AT&T Park.
But all anyone wanted to talk about after -- for better or worse -- was Pagan's catch and how it shifted the momentum in the amount of a time it takes to leave your feet for a catch.
"It's hard to see a better play in baseball than that ... especially with what was on the line," said Giants manager Bruce Bochy.
The Padres (41-58), who have dropped the first two games of this three-game series, looked to be in a good spot in the eighth inning after Headley singled with one out.
That brought up Quentin, who doubled earlier and hit a ball even harder in the third inning, a ground ball that second baseman Ryan Theriot turned into a double play.
Quentin jumped on a pitch from reliever Sergio Romo and sent it into the gap in left-center field. Pagan got a great jump on it and made a diving catch near the warning track.
"I was shocked," Quentin said. "I hit it and immediately my first thought was Chase was scoring."
Then in the ninth inning, Padres reliever Joe Thatcher (0-4) walked left-hander Brandon Belt on a close pitch to start the inning.
"I think it was definitely a good pitch that could have gone either way," Thatcher said.
Pagan then singled to left field to bring up the left-handed-hitting Crawford, who was hitless in three at-bats to that point. Before Crawford delivered the game-winning hit, Padres catcher Yasmani Grandal was charged with a passed ball that allowed the runners to advance to second and third base.
The left-handed Thatcher, who entered the game having allowed lefties to hit at a .116 clip, tried to go away with a pitch, but Crawford got the barrel on it, sending it into center field to end the game.
Lost in the wild finish were two strong performances by each starting pitcher, though it certainly didn't start out that way.
San Diego right-hander Edinson Volquez, coming off a one-hit shutout, allowed two runs in the first inning, but then settled down and got a lot of mileage out of his curveball.
"The curveball was really good tonight," Black said. "Outstanding. As the game went on, he got better. He pitched a great game."
Volquez allowed three hits and two runs -- all coming in the first inning -- over seven innings with three walks and eight strikeouts.
"I had a better rhythm after the first inning," Volquez said. "I really wanted to get ahead in the count, and I think I did that. ... And I stayed in the game."
San Francisco southpaw Madison Bumgarner allowed both Padres runs in the second inning and then little else. All told, Bumgarner allowed two runs on six hits with two walks and nine strikeouts.
"I was behind a lot. That was probably the least amount of fastball's I've ever thrown in a game, ever. My command was a little off," Bumgarner said. "The defense made some pretty awesome plays. There were a few times when I got lucky and they hit it right toward them."