The Nationals took the lead in the bottom of the first after a solo homer by Jayson Werth and a run-scoring single from Wilson Ramos. But Padres right-hander Luis Perdomo rebounded after that two-run first to shut the Nationals down the rest of the way and lasted a career-high seven innings.
Then, Kemp struck again in the fifth inning. Roark allowed a run-scoring single to Melvin Upton Jr., followed by a walk to Ryan Schimpf before Kemp hammered a 2-1 fastball for a three-run homer. Roark allowed five runs on six hits in five innings, his shortest start since June 5.