SAN FRANCISCO -- Nate Schierholtz blasted a Sergio Romo fastball into the first row of the right field pavilion at AT&T Park for a ninth-inning home run that broke a scoreless tie and delivered the Chicago Cubs a 1-0 victory over the San Francisco Giants on Saturday night.
Romo (3-6), the losing pitcher on Friday night after a two-out error by Brandon Belt in the ninth inning, was facing just his second batter in relief of Madison Bumgarner, who shut out the Cubs for eight innings.
The All-Star was matched pitch for pitch by fellow left-hander Chris Rusin, who was making just his third start of the season for the Cubs. Rusin, who had never finished the sixth inning in any of his nine previous career starts, turned the ball over to reliever Pedro Strop (1-0) after seven shutout innings.
After the Giants blew a golden opportunity to score in the eighth, Schierholtz stunned the fans of his former team by towering his 14th home run barely over the 20-foot-high brick wall just to the left of the 365-foot mark. It was his third home run in eight games on the Cubs' current road trip.
As they had an inning earlier, the Giants loaded the bases in the ninth, this time against Cubs closer Kevin Gregg. But pinch-hitter Tony Abreu grounded into a double play to end it for his second save in two nights and 21st in 24 opportunities this season.
Coupled with Friday's dramatic win, the Cubs clinched the three-game series in San Francisco. They have now won or split six of their last seven road series and, at 5-3, assured themselves of a winning record on a nine-game trip that ends Sunday against the Giants.
The loss was the Giants' sixth in their last seven games and 18th in 25 games against National League Central competition this season.
One night after the Cubs' Edwin Jackson and Giants' Matt Cain took dueling shutouts into the sixth inning, Rusin and Bumgarner were even better. They carried a 0-0 game into the eighth, with Rusin leaving first, replaced to start the bottom of the inning by Strop.
Rusin, who was coming off a win at Arizona in which he pitched five innings, struck out three in his seven shutout innings. He allowed three hits and two walks.
Thanks to two mental mistakes by Strop consecutive bunts, the Giants nearly broke through against the reliever in the eighth.
But after loading the bases on a walk to pinch-hitter Gregor Blanco and bunts by Andres Torres and Marco Scutaro on which the Cubs failed to get anyone out, Strop ran his string of consecutive scoreless innings for Chicago to 9 2/3 by getting outs at the plate on ground balls by Buster Posey and Pablo Sandoval and then striking out Hunter Pence.
Blanco was pinch-hitting for Bumgarner, ending the left-hander's night after eight scoreless innings. Bumgarner, like Rusin, did not factor in the decision.
Bumgarner gave up four hits and two walks in his eight innings. He struck out seven in his eighth consecutive start allowing two or fewer earned runs.
Two defensive gems -- one by each team - kept the game scoreless entering the ninth.
The Cubs threatened to score in the top of the sixth when, with runners on first and second, Schierholtz smoked a line drive to center field. But Torres, the Giants' center fielder, raced in and made a diving catch to end the inning.
Pence led off the Giants' seventh with a double and advanced to third on Jeff Francoeur's grounder to second. After Joaquin Arias grounded out with Pence holding third, Brandon Belt's bid for a shutout-ending single was nabbed by leaping Cubs first baseman Anthony Rizzo.
Rusin carried a perfect game into the fifth inning. That ended with a one-out walk to Pence, and his no-hitter was gone two batters later when Joaquin Arias spanked a single up the middle, just out of the reach of diving second baseman Darwin Barney.
The left-hander got out of his first jam of the night when Belt hit the first pitch he saw on the ground right to Barney, standing two base runners.
Rusin needed just 27 pitches to go one time through the Giants' lineup. Among the nine batters, only one pulled the ball on him -- Bumgarner, who grounded out to third baseman Cody Ransom.
The Cubs had four base runners in the first five innings against Bumgarner, but none reached scoring position. Two of the four Cubs who reached base during that stretch did so via Giants errors.
NOTES: Rusin's only other two starts for the Cubs this season had come as a last-minute replacement for a traded pitcher -- RHP Scott Feldman, dealt July 2 to Baltimore, and RHP Matt Garza, traded Monday to Texas. Both times, Rusin started the day with the Cubs' Triple-A affiliate in Iowa and had to travel to Oakland and Arizona. ... The Cubs' starting lineup included Giants castoffs Ransom, Schierholtz and LF Cole Gillespie. ... Giants RHP Ryan Vogelsong gave up a two-run homer -- the only hit he allowed -- in a 45-pitch, 2 2/3-inning stint for Class A San Jose on Friday night. The former All-Star's next injury-rehab start will come for Double-A Richmond (Va.) after he joins the Giants for their White House visit on Monday. ... With Friday's trade that sent LF Alfonso Soriano to the New York Yankees, the Cubs do not employ a player who was on the 2007 National League Central champion team. Only RHP Jeff Samardzija remains from the 97-win Cubs team of 2008.