San Diego built a three-run first inning lead then hung on the rest of the game to beat the Washington Nationals 4-2 Saturday night at Petco Park.

Nick Hundley hit a three-run home run with two outs in the first inning to stake the Padres to the early lead. The inning should have ended after three batters but Washington second basemen Adam Kennedy made an error that allowed Adrian Gonzalez to get on base and prolong the inning. Chase Headley singled after that then Hundley hit his blast.

It was an undesirable start for Washington starter J.D. Martin (0-1), who went six innings allowing four runs (only one earned) on four hits and no walks. He struck out five.

Kennedy and Wil Nieves knocked in runs in the second inning to cut the lead to 3-2, but that was as close as the Nationals would get.

Padres starter Mat Latos (5-3) also went six innings, yielding just the two runs while striking out eight. He gave up two hits and three walks. Luke Gregerson and Mike Adams pitched scoreless innings of relief to get to closer Heath Bell, who worked a perfect ninth for his 14th save of the season.

Chris Denorfia had an RBI groundout in the fourth inning to extend the lead to 4-2 for San Diego, who have won five of seven and sit atop the National League West standings.