Recap: San Francisco vs. Arizona

San Francisco, CA (Sports Network) - Barry Zito worked into the eighth inning as the San Francisco Giants opened a three-game set against the Arizona Diamondbacks with a 4-2 victory at AT&T Park.

Zito (4-2) allowed just two runs on seven hits and a walk while striking out three to earn the victory. Clay Hensley finished the eighth and Santiago Casilla allowed two hits in the ninth, but recovered to record his 13th save of the season.

"I wanted to throw more strikes and let them hit it," Zito said. "I wanted to pitch to contact instead of trying to nibble. Just pouring it through the zone, putting pressure on them."

Brandon Belt went 2-for-4 with an RBI triple, while Hector Sanchez and Gregor Blanco also knocked in runs for the Giants.

Justin Upton ripped an RBI double and John McDonald laced a pinch-hit solo homer for the D-backs, who had a brief two-game winning streak snapped.

Trevor Cahill (2-5) was saddled with the loss after allowing four runs on eight hits and two walks with five strikeouts over six-plus innings.

The Giants jumped on top early, plating three runs in the first inning. Blanco opened the frame with a double and moved to third on a sacrifice bunt by Brandon Crawford. Angel Pagan walked to put runners on the corners and, with Sanchez at the plate, the Giants executed a perfect double steal which allowed Blanco to score. Sanchez then ripped a single into right to score Pagan and Belt laced a triple into the alley in right-center to bring in Sanchez.

Emmanuel Burriss opened the Giants' second at-bat with a single, advanced to second on a sac-bunt by Zito and scored on a double by Blanco to extend the San Francisco lead to four.

Cahill and Willie Bloomquist hit back-to-back singles in the Arizona fourth and Cahill came around to score on a ground-rule double by Upton to cut the deficit to three.

McDonald led off the Diamondbacks eighth by crushing a 1-2 fastball from Zito over the wall in left to make it 4-2.

Casilla allowed back-to-back base hits to Paul Goldschmidt and Chris Young. Miguel Montero struck out of the second out of the inning and Ryan Roberts came up as the last hope for Arizona. He launched a fly ball deep into right field which got Blanco turned around, but he recovered to make an over-the- shoulder catch to end the game.

"We've had some pressure and seen some better at-bats, we had our opportunities today," Diamondbacks manager Kirk Gibson said. "We hit some balls hard, right at guys, but if you play better baseball, it doesn't make much of a difference. It should have been a different ball game."