Giants 1, Cardinals 0: Barry Zito tossed seven strong innings and San Francisco won its fifth straight home opener.

Zito (1-0) allowed three hits with four strikeouts, picking up where he left off last season when he shut out the Cardinals for 7 2/3 innings in Game 5 of the National League Championship Series. Sergio Romo worked a perfect ninth for his third save.

The Giants scored in the fourth when they loaded the bases after Yadier Molina mishandled Zito’s bunt with one out. Cardinals starter Jake Westbrook (0-1) walked the next batter - Angel Pagan.

Westbrook allowed six hits and six walks while throwing 116 pitches in 6 2/3 innings, but the Cardinals’ offense didn’t offer much support. St. Louis was held to three hits, including two by Allen Craig.

Zito's outing continued a stellar run by San Francisco's starting pitchers, who have not allowed an earned run through their first four games covering 26 innings.

GAME NOTEBOOK: The Giants raised their 2012 World Series championship banner in a pregame ceremony. ... Cardinals 3B David Freese (back) was expected to begin a minor league rehab assignment Friday with Triple-A Memphis. …St. Louis RF Carlos Beltran has one hit in his first 10 at-bats after going 0-4 against the Giants.