Alfonso Soriano's three-run home run powered 2 victory over the Padres in the second contest of a three- game series.
The hit made a winner of Matt Garza (10-10), who tossed seven innings, allowing two runs on five hits and two walks while striking out eight in his fourth straight winning decision.
"I'm going to try and improve. That's all I can do. I've got another year under my belt and a couple more lessons learned," Garza said about his season.
Chad Qualls (6-8) surrendered Soriano's homer to take the loss. Anthony Bass made his third start of his career and allowed one run on five hits and two walks through five full frames.
"I like the way he mixed his pitches today," Padres manager Bud Black said about Bass. "We're seeing a guy who looks as though he feels he belongs."
Kyle Blanks knocked in both of the Padres' runs as they were defeated for the third time in five games.
Blanks' two-run double in the second gave the Padres an early lead. They then put runners on second and third with two outs in the frame, but Will Venable struck out swinging to end the inning.
The Cubs closed the gap in the fourth when Aramis Ramirez led off the frame with a homer.
After stranding a runner on third in the fifth and seventh innings, Soriano's three-run blast in the eighth gave the Cubs a 4-2 lead.
San Diego left the tying runs on second and third in the eighth before Blake DeWitt's pinch-hit, two-run single in the ninth put the game away for Chicago.
Ramirez was in the lineup after missing the previous four games with a strained right quad...Cubs shortstop Starlin Castro went 2-for-5 to extend his hit streak to 10 games and has now reached base safely in a career-high 39 straight games...Garza is 6-2 over his past 11 starts and has not allowed more than three earned runs in any game of that span.