The Diamondbacks have captured 16 of their last 19 games and own a three-game lead in the National League West.

Mark Reynolds added three RBI and Miguel Montero had two in support of Livan Hernandez (8-7), who gave up four runs over seven innings for the win.

Washington was hot too, coming into the game with eight wins in its last 10 games, but both Matt Chico and Saul Rivera gave up four runs. Rivera (4-4) took the loss in relief, allowing his four runs while retiring only one batter.

After the Nationals rallied from four runs down to tie it, Arizona scored five times in the seventh, with Reynolds' two-run single breaking the tie.

Jackson's first homer came in the opening inning and he added insurance with another blast in the eighth.