Young (3-2) allowed only three hits and three walks and struck out eight for the Padres, who had lost two straight and six of eight entering the game. Hoffman pitched a perfect ninth to record his sixth save of the season.
Kevin Kouzmanoff hit an RBI triple and scored for San Diego, which won despite managing only four hits.
The Nationals wasted a strong effort by Shawn Hill (2-3), who gave up three runs on four hits and three walks. He struck out five in 6 1/3 innings.