Hundley's blast in the first inning got the Padres off to a good start and Chris Denorfia added San Diego's other RBI with a fourth-inning groundout.
The win was the fifth in seven games for the first-place Padres, who benefited from another good performance from Latos (5-3). The San Diego hurler allowed two runs on four hits over six innings, walking three and fanning eight.
J.D. Martin (0-1), called up from Triple-A Syracuse to make his first start of the year for the Nationals, absorbed the loss. Adam Kennedy's fielding error opened the door for Hundley's homer, meaning three of the four runs Martin allowed were unearned.
Kennedy and Will Nieves notched Washington's RBI in the loss.
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