San Francisco 4, Arizona 2

Giants 4, Diamondbacks 2: Gregor Blanco stole home as part of a three-run first inning and Barry Zito earned his fourth win as San Francisco edged visiting Arizona in the opener of a three-game series.

After lasting a season-low three innings in his last start, Zito (4-2) allowed one run on six hits over 7 1/3 frames. Santiago Casilla worked around two baserunners in the ninth for his 13th save.

Blanco led off the bottom of the first with a double and scored on a double steal when Angel Pagan took second base. Hector Sanchez and Brandon Belt followed with run-scoring hits off Trevor Cahill (2-5), who gave up four runs over six innings.

San Francisco extended its lead in the second when Blanco’s double scored Emmanuel Burriss, who singled to lead off the inning.

The Diamondbacks scored a run in the fourth on Justin Upton’s RBI double and knocked Zito out of the game when pinch hitter John McDonald belted a solo home run in the eighth.

Melky Cabrera, who hit .452 with two home runs during the Giants’ last seven games, went 1-for-3 and leads the majors with 74 hits.

GAME NOTEBOOK: Arizona C Miguel Montero went 0-for-4 after missing the past five games with a groin injury. … The Giants have won 11 of their last 17 games and seven of their last 10 at home. … Diamondbacks manager Kirk Gibson celebrated his 55th birthday. …San Francisco improved to 22-0 when leading after eight innings. …The Giants are 7-12 against Arizona since June 14, 2011.

• San Francisco will play their next game at home against Arizona. The Giants have a W/L % of .520 after a win and .542 after a loss.
• Arizona will play their next game on the road against San Francisco. The Diamondbacks have a W/L % of .435 after a win and .462 after a loss.