"The whole team really made that moment happen, it's not just me," said Pence, who was pushed out of the dugout by Melky Cabrera for a quick curtain call after his blast broke a 6-6 tie. "Hopefully there's a lot more of those, there's a long way to go."
Pence's home run was preceded by an impressive at-bat from Buster Posey, who battled his way through nine straight fastballs from Betancourt to hit the game-tying sacrifice fly.
"Those are moments that make this game so exciting," Bochy said. "They had their closer out there. He throws great and is having a great year, and you have a great hitter with the game on the line. He kept coming at him, and Buster was just fouling them off. It's what you live for, that kind of competition, and Buster found a way to get it done. That was big for us."
The bullpen squandered a one-run lead and allowed three runs after taking over for starter Barry Zito in the sixth, but the Giants won the rubber match of the three-game series with a five-run eighth inning. The win keeps the Giants atop the National League West, a game ahead of the Dodgers, who beat the Marlins, 5-0, earlier in the day.
Entering the inning trailing, 6-4, the Giants opened the bottom of the eighth by loading the bases with no outs. Brandon Crawford hit a bloop single to left and Hector Sanchez followed with a pinch-hit ground-rule double, with Angel Pagan following with a walk.
After a Marco Scutaro popout to left, a diving Josh Rutledge wasn't able to handle Cabrera's sharp infield single to short, which drove in Crawford. Posey's sacrifice fly to left tied the game at 6 when it scored Joaquin Arias, who had been pinch-running for Sanchez, and Pence followed with his go-ahead home run.
"We've had some situations earlier this year where we didn't make that happen, and it was just poetic justice with Pence coming up there and doing his thing," Zito said.
George Kontos replaced Zito in the sixth and allowed a game-tying DJ LeMahieu double that drove in Jordan Pacheco and then a go-ahead RBI single from Carlos Torres, which was the reliever's first career hit. Dexter Fowler later scored in the seventh on Pacheco's sacrifice fly to center off Clay Hensley to take a 6-4 lead.
The Rockies' two-run sixth followed Ryan Theriot's two-out double to left field in the bottom of the fifth that scored Brandon Belt from second to break a 3-3 tie.
Zito battled through 5 1/3 innings, and was charged with four earned runs on seven hits.
"I lost my rhythm kind of through the middle innings, but in the front and back of the outing, I felt pretty good about eliminating the timing issues that make the command go away," Zito said.
The back-and-forth affair started when the Giants jumped to a quick three-run lead in the first inning on Cabrera's two-run single up the middle and Belt's single that scored Cabrera.
The Rockies first got on the board in the third when Eric Young and Rutledge hit back-to-back RBI doubles off Zito, and then tied the game at 3 runs in the fourth when pitcher Alex White's sacrifice fly to left field scored Wilin Rosario.
"A lot of things happened in that game," Bochy said. "It was like a season almost, with all the ups and downs in one ball game. ... You keep fighting, keep going until the end, and these guys did it."