San Francisco, CA -- (Sports Network) - Matt Cain allowed just two runs over eight innings and hit his second home run of the year as the San Francisco Giants edged the Houston Astros, 4-2, in the second of a four-game set at AT&T Park.

Cain (2-3) surrendered just seven hits while striking out four and walking five for the Giants, who have won three of four. Brian Wilson notched his National League-leading 12th save.

"I was a little bit wild in the first two innings," Cain said. "I just tried to make myself calm down, find that good groove that I found in the bullpen and it finally clicked in the third. I was able to go in there and throw strikes where I wanted to."

Fred Lewis, who hit for the cycle exactly one year ago, fell a homer short after a 3-for-4 performance. Omar Vizquel and Randy Winn each doubled and scored a run.

Carlos Lee homered and drove in both runs for the Astros, who had a four-game win streak snapped and lost for just the second time in their last 11. Brandon Backe (2-5) allowed four runs -- three earned -- on seven hits over six innings.

The Giants pounced on Backe in the first, as Lewis led off with a triple, then Vizquel and Winn laced back-to-back RBI doubles to right. Bengie Molina's fly ball to right moved Winn to third, and Winn came in to score and give the Giants a 3-0 lead on a passed ball.

"I guess Lewis is seeing the ball pretty good right now," Backe said. "He got an inside fastball. When the first batter of the game gets a triple you want to limit it to just him scoring and leave at that. The ball dropped and Vizquel made it to second on hustle and scores on the next play. The passed ball was a cutter that cut quite a bit. I didn't throw the ball horribly."

Houston grabbed a run on three straight singles with one out in the top of the third, as Miguel Tejada, Lance Berkman and Lee carved out consecutive base hits, with Lee's line drive plating Tejada.

Cain helped his own cause with a leadoff homer in the fifth, and while Lewis followed with a single up the middle, the Giants couldn't produce anything more.

Houston couldn't put anything else together against Cain until the eighth, when Lee launched a one-out fly ball to left that went just over the glove of a leaping Lewis for Lee's eighth homer of the season, cutting the lead to 4-2.

Cain issued a two-out walk to Hunter Pence, but recovered to strike out J.R. Towles to preserve the two-run edge. Wilson made short work of the Astros in the ninth for the save.

Game Notes

Molina played in his 1,000th career game...Berkman extended his hit streak to 12 games, but had a 15-game run-scoring streak snapped. The streak tied Carlos Beltran for the longest in franchise history...Pence went 1-for-3 to extend his hit streak to 10 games...Pence and second baseman Kaz Matsui collided on Molina's eighth inning single, but both players remained in the game...Brian Moehler (1-0) toes the rubber for the Astros on Wednesday against Pat Misch (0-0).