Nationals 8, Padres 5
Rookie Bryce Harper belted his first career homer and Ian Desmond collected three hits - including a two-run double in the sixth inning - as host Washington posted its fourth win in five outings.
Playing in his 15th career game, Harper launched a 2-1 breaking ball from Tim Stauffer over the wall in straightaway center field in the third inning. Harper, who raced around the bases before settling into the dugout, was summoned for a curtain call to commemorate the milestone.
The 19-year-old Harper is the youngest player to belt a home run in the majors since 1988, when Adrian Beltre recorded seven prior to turning 19 1/2 years of age.
Chad Tracy blasted a pinch-hit homer, Xavier Nady also went deep and Desmond scored twice as the Nationals improved to 13-4 at home.
With San Diego clinging to a 5-4 lead, Desmond deposited an offering from Miles Mikolas (0-1) off the wall in right center to plate Rick Ankiel and Jesus Flores.
Craig Stammen (3-0) struck out three in two scoreless innings in pick up the win in relief of starter Ross Detwiler. Sean Burnett induced a double play to end the threat in the ninth for his first save of the season.
Orlando Hudson had a two-run single, Chase Headley delivered a run-scoring single and Yonder Alonso scored twice for the Padres, who fell to 3-10 on the road.
GAME NOTEBOOK: Making his first start, Washington catcher Sandy Leon exited the contest after a collision with Chase Headley at the plate in the top of the fourth inning. Leon, who suffered a right ankle sprain, was replaced by Flores. ... Stauffer, who was activated from the disabled list prior to the game, was making his season debut after being sidelined with a strained right elbow. He allowed four runs on seven hits in five innings.