SAN FRANCISCO -- They arrived in San Francisco on Monday feeling jet-lagged, but the Red Sox left on Wednesday with a series victory after a commanding 12-1 win over the Giants.

San Francisco left-hander Barry Zito didn’t make it through the fourth inning, while Red Sox starter Felix Doubront countered with a strong performance. Coming off of two straight outings that lasted just four innings each, Doubront finished eight innings on Wednesday, allowing an earned run on five hits and a walk while striking out three.

The Red Sox hit Zito hard, but the Giants’ subpar defense didn’t hurt, either.

Following a two-run homer by Will Middlebrooks in the second inning, the Red Sox pulled away with three more in the third. The rally was aided by a miscue by Giants first baseman Brandon Belt, who didn’t have his foot on the bag and allowed Shane Victorino to leg out an infield single. The next batter, Dustin Pedroia, ripped a double down the left-field line to score Jacoby Ellsbury before Jonny Gomes drove in two more with a soft single to left.

Zito was stung by his defense again in the fourth inning when Victorino blooped one to right field that landed among three Giants, allowing Middlebrooks to score and make it 6-1 Red Sox. It was the final straw for Zito, who lasted 3 2/3 innings, allowing six earned runs on seven hits and two walks while striking out three.

In the seventh, the Sox sent the home fans to the exits while giving their loud traveling contingent plenty to cheer about, tacking on five more runs. Jarrod Saltamacchia started off the salvo with a two-run single before Stephen Drew hit a three-run blast to right field.

Prized prospect Xander Bogaerts made a late cameo, entering as the third baseman in the bottom of the seventh inning, with Middlebrooks moving to second base for Pedroia. Less than 24 hours after making his MLB debut, Bogaerts reached base for the first time of his career when pitcher Michael Kickham threw the ball into center field on a potential double play ball. The error allowed Daniel Nava to score from second and pushed Boston’s lead to 12-1.

David Ortiz started the contest at first base but was replaced by Mike Napoli in the bottom of the fifth after experiencing lower back tightness. Ortiz, playing first for the second time in three days, went 0-for-3 at the plate but took part in a well-executed rundown in the first inning.

With the victory, Boston (75-54) moved a half-game ahead Tampa Bay (72-52) for first place in the AL East, pending the Rays' night game in Baltimore. Meanwhile, the Red Sox will fly down to Los Angeles for their first matchup with the Dodgers since last year’s blockbuster trade, opening a three-game series on Friday.