Clayton Kershaw outpitched Yusmeiro Petit for his major league-leading 19th win, and the Los Angeles Dodgers moved three games ahead of San Francisco in the NL West with a 4-2 victory over the Giants on Sunday.Los Angeles Dodgers pitcher Clayton Kershaw throws to the San Francisco Giants during the first inning of a baseball game, Sunday, Sept. 14, 2014, in San Francisco.Los Angeles Dodgers' Matt Kemp rounds second base after hitting a two-run home run against the San Francisco Giants during the sixth inning of a baseball game, Sunday, Sept. 14, 2014, in San Francisco.Los Angeles Dodgers' Matt Kemp (27) is greeted by Adrian Gonzalez after hitting a home run against the San Francisco Giants during the sixth inning of a baseball game, Sunday, Sept. 14, 2014, in San Francisco.San Francisco Giants pitcher Yusmeiro Petit throws to the Los Angeles Dodgers during the first inning of a baseball game, Sunday, Sept. 14, 2014, in San Francisco.