Nationals 7, Rockies 1: Stephen Strasburg recovered from his worst start of the season by striking out eight in 7 2/3 innings and Jayson Werth drove in three runs as host Washington won its fourth straight game.Anthony Rendon recorded two RBIs and Ryan Zimmerman added one as the Nationals outscored Colorado 14-4 while winning the first two games of the series. Strasburg (7-6), who yielded seven runs in a 9-2 loss at Milwaukee on Wednesday, allowed one run and five hits while improving to 6-0 in his last nine turns at home.DJ LeMahieu homered and Wilin Rosario had two hits for the Rockies, who lost for the 13th time in 15 games and are 1-8 in their last nine road contests. Christian Friedrich (0-3) yielded five runs, five hits and and four walks in 3 1/3 innings in his third start of the season as Colorado's major league-worst ERA rose to 4.99.Friedrich was in trouble immediately after walking Denard Span and Rendon to lead off the first, and Werth made him pay with a smash down the line that ate up third baseman Ryan Wheeler for a two-run double. After Adam LaRoche reached on an infield hit, Zimmerman capped the uprising with a sacrifice fly.Washington broke it open with four runs in the fourth as Strasburg doubled with one out and Span singled before Rendon doubled them home, and Werth followed with an RBI double and scored on a wild pitch. LeMahieu ripped a 1-2 offering out to left-center with one out in the eighth to break up the shutout.GAME NOTEBOOK: Rockies SS Troy Tulowitzki, who leads the majors with a .353 batting average, was given the night off and has yet to face Strasburg. ... The Nationals lowered their major league-leading ERA to 3.04. ... Washington improved to 37-3 when scoring four or more runs this season.