Pitching with a big lead in the eighth inning, Clayton Kershaw bounced a curve in the dirt, then spun in disgust and kicked the mound as if he had just lost the game. Kershaw is unaccustomed even to one-pitch lapses, and he overcame the occasional difficulty he had Thursday, pitching eight innings to help the Los Angeles Dodgers win their third game in a row by beating the Miami Marlins 6-0.