Angel Pagan led off the first inning with a homer, Buster Posey connected two batters later, and Yusmeiro Petit went six innings in a spot start replacing injured Matt Cain and the San Francisco Giants beat the San Diego Padres 6-0 on Tuesday night.San Diego Padres starting pitcher Eric Stults stands on the mound after giving up a home run to the San Francisco Giants' Buster Posey, rear, in the first inning of a baseball game Tuesday, April 29, 2014, in San Francisco.San Francisco Giants' Buster Posey watches his home run to left field off San Diego Padres starting pitcher Eric Stults in the first inning of a baseball game Tuesday, April 29, 2014, in San Francisco.San Francisco Giants relief pitcher Yusmeiro Petit reacts after San Diego Padres' Cameron Maybin grounded out to end the sixth inning of a baseball game Tuesday, April 29, 2014, in San Francisco.San Francisco Giants home run king Barry Bonds, left, gestures while talking with Giants relief pitcher Sergio Romo during batting practice before the Giants' baseball game against the San Diego Padres on Tuesday, April 29, 2014, in San Francisco.