"You can't play with revenge on your mind, because you end up trying too hard," said right-hander Jake Peavy, who won his second straight start. "But I think the boys did a great job of coming out and knowing they would have a great game."
Playing without catcher Buster Posey, who sat out with tightness in his left hip, the Giants jumped on Cubs starter Edwin Jackson (6-14) to grab a five-run lead after three innings. They scored four runs in the first after Angel Pagan and Hunter Pence singled to set up the outburst. Pablo Sandoval's sacrifice fly opened the scoring. After Michael Morse walked, Joe Panik collected the first of his three hits, a single that delivered Pence. Travis Ishikawa, who also amassed three hits, lined a two-run double.
Chicago halved the difference in the second inning on Chris Valaika's two-run homer off Peavy. The Giants responded with three runs in the third. Morse and Ishikawa doubled before Andrew Susac belted his first Major League home run, an opposite-field drive to right.
Susac received some good-natured kidding from left-hander Madison Bumgarner upon returning to the dugout. According to Susac, Bumgarner said, "It's too bad you hit your first home run at a small field like this," referring to Wrigley Field's cozy dimensions.
In the fourth inning, Pence accounted for San Francisco's final run with his team-leading 17th homer. All but five of those homers were hit on the road.
Peavy allowed two runs in seven innings while improving to 8-5 with a 2.76 ERA in 16 career starts against Chicago. Though he yielded 10 hits, he compensated by walking none and fanning eight.
"That kind of goes hand in hand with the game," Peavy said, pointing out that with such a sizable lead, "You can be more aggressive in the zone."
The Giants are now three games behind the first-place Dodgers in the National League West, and have inched 1 1/2 games ahead of the Braves in the race for the NL's second Wild Card spot.
Chris Haft is a reporter for MLB.com. Read his blog, Haft-Baked Ideas, and follow him on Twitter at @sfgiantsbeat. This story was not subject to the approval of Major League Baseball or its clubs.