San Francisco, CA (Sports Network) - Nate Schierholtz's pinch-hit RBI single in the sixth put San Francisco ahead, and the Giants held on for a 4-2 win over the Arizona Diamondbacks in the opener of a three-game series.
The victory, combined with San Diego's loss to Chicago on Tuesday, gives the Giants a two-game lead in the NL West. It is critical separation for San Francisco, which has a magic number of four and finishes the season with a home series against the Padres.
"It feels good," Schierholtz said. "We know we have six games left and every game is huge, obviously. It's a big game for us to start the homestand."
Pat Burrell went 2-for-4 with an RBI single and Juan Uribe homered for the Giants, who have won four of five. Starter Jonathan Sanchez (12-9) got the victory after limiting the Diamondbacks to two runs on three hits and four walks in six innings, while striking out six.
Kelly Johnson went 2-for-3 with a home run for Arizona, which had won five of six entering the series.
In a 2-2 game, Pablo Sandoval doubled off Diamondbacks starter Rodrigo Lopez (7-15) with two away in the sixth. Schierholtz entered as a pinch-hitter for Sanchez, and took a fastball the other way, lining it to left to plate Sandoval.
"It was his game," Arizona manager Kirk Gibson said of Lopez. "He pitched well for us and I would never take him out in that situation."
Mike Hampton came in and got the final out, and after Ramon Ramirez threw a scoreless top of the seventh, the Giants added an insurance run in the bottom half.
Mike Fontenot led off with a walk against Jordan Norberto, who then struck out Aubrey Huff -- though a wild pitch allowed Fontenot to move to second. Blaine Boyer came in to pitch and got Buster Posey to ground out, but Burrell followed with a single up the middle to make it a 4-2 game.
Facing Giants relievers Sergio Romo and Javier Lopez, Arizona put runners on the corners with one out in the eighth. However, closer Brian Wilson came in and got the final five outs for his 46th save.
Lopez gave Arizona its first run with a sacrifice fly in the second inning, and Johnson's one-out solo blast in the third made it a 2-0 game.
But the Giants got one run back in the home half of the third, when Andres Torres led off with a triple before scoring on Fontenot's base hit. Uribe began the fourth by blasting a first-pith slider over the left field wall.
With two more saves, Wilson will equal the franchise record for saves in a season, held by Rod Beck (48 in 1993). Wilson sits alone in second place, as he passed Robb Nen (45 in 2001) with Tuesday's save ... The Giants lead the season series, 11-5 ... Sandoval finished with two hits for San Francisco.