Hero: Randy Wells (8-13) allowed six hits over 7 2/3 shutout innings while striking out six and walking one to lead the Cubs to their 11th shutout victory of the season.
Goat: Aramis Ramirez, now hitting .238, went 0-for-4 and was the only Cubs starter other than Wells who did not reach base.
Key Play: Carlos Marmol relieved Wells with two outs in the top of the eighth with runners at second and third and struck out Freddy Sanchez to escape the jam. Marmol, who earned his 34th save, struck out four of the five batters he faced. The 27-year-old Dominican right-hander has 128 strikeouts in 72 2/3 innings for an incredible ratio of 15.85 strikeouts per nine innings.
Comments: The Giants (85-67) fell out of first place in the NL West and trail the San Diego Padres by a half-game.
The Cubs (69-82) improved to 18-8 under interim manager Mike Quade.
Kosuke Fukudome (1-for-2) hit his 13th homer of the season in the third inning. Fukudome (.274 on the season) is hitting .316 since the All-Star break after hitting .252 in the first half.
The game's other run scored in the bottom of the fifth when Koyie Hill reached with a leadoff double, advanced to third on a wild pitch by San Francisco starter Jonathan Sanchez (11-9), and scored an unearned run on a throwing error by rookie catcher Buster Posey.
Next: Ryan Dempster (14-10, 3.50 ERA) will try for his seventh win over a 10-start span Thursday (CSN, 6:05 p.m.) against San Francisco in the last night game of the season at Wrigley Field. Dempster has worked seven shutout innings in each of his last two starts, at Milwaukee and at FGlorida.
The Giants will counter with rookie left-hander Madison Bumgarner (5-6, 3.27). The 21-year-old Bumgarner allowed three runs in 5 2/3 innings against the Cubs on Aug. 9 and did not figure in the decision.
Note Thursday's earlier than usual start time.