SAN FRANCISCO — Barry Zito pitched another gem against the St. Louis Cardinals, leading the San Francisco Giants to a 1-0 victory in their home opener Friday. The Giants celebrated their latest World Series title throughout the day. Of course, it was Zito who saved San Francisco's season by beating the Cardinals 5-0 last fall in Game 5 of the NL championship series. This time, Zito outdueled Jake Westbrook (0-1) in his season debut. The lefty also had a key sacrifice bunt that led to San Francisco's run in the fourth, when Angel Pagan drew a bases-loaded walk. The Giants won their 15th straight game with Zito on the mound, including the postseason. He hasn't lost since Aug. 2 against the New York Mets. Zito (1-0) blanked the Cardinals on three hits through the seventh. San Francisco's starters have gone 26 innings without allowing an earned run so far. Jeremy Affeldt pitched a 1-2-3 eighth and Sergio Romo closed out the three-hitter with a clean ninth for his third save. Fresh off San Francisco's second title in three years, manager Bruce Bochy carried the World Series trophy out from an entrance in center field as the first Giant announced to the sellout crowd of 41,581. Dodgers 3, Pirates 0: Zack Greinke pitched two-hit ball into the seventh inning of his splendid Dodgers debut against Pittsburgh. Andre Ethier homered and Los Angeles got consecutive RBI doubles from Matt Kemp and Adrian Gonzalez. Greinke, who signed a $147 million, six-year contract to join the Dodgers during the offseason, struck out six and did not walk a batter in 6 1-3 innings. Reds 15, Nationals 0: Todd Frazier and Zack Cozart each hit two of Cincinnati's six home runs, including a grand slam by pinch-hitter Xavier Paul, as the Reds sent Washington to its first loss of the season. It was the Nationals' most lopsided loss since baseball returned to Washington in 2005, topping a 15-1 defeat to Detroit on June 19, 2007, according to STATS. Washington had been the last major league team without a loss this season. Braves 4, Cubs 1: Justin Upton hit his third homer in four games and Mike Minor pitched into the eighth inning to help Atlanta beat Chicago. Other results: Marlins 7, Mets 5; Diamondbacks 3, Brewers 1; Rockies 5, Padres 2. Inter-League Royals 13, Phillies 4: Alex Gordon and Chris Getz each hit a bases-loaded triple, and Kansas City rallied to spoil Philadelphia's home opener. The inter-league matchup was a rare one between teams that first met in the 1980 World Series — the Royals' only other visit to Philadelphia came in 2004. Domonic Brown and Erik Kratz hit solo homers for the Phillies, who are off to a 1-3 start. — Agencies