Stephen Strasburg won his ninth game, and Jayson Werth hit a pinch-hit grand slam to break open a close game to key a 10-2 Washington Nationals win over the St. Louis Cardinals on Sunday.
Strasburg (9-0, 2.69 ERA) gave up a run on six hits in six innings, striking out four and walking two.
A Matt Adams sacrifice fly in the seventh off reliever Felipe Rivera pulled the Cardinals (26-25) to within 3-2.
Anthony Rendon hit a solo shot in the bottom of the seventh to push the lead to 4-2, and later in the inning Werth connected off St. Louis reliever Dean Kiekhefer for the grand slam that made it 8-2 Nats.
Wilson Ramos had a two-run single in the fourth and a solo homer in the eighth for Washington (30-21).