Washington, DC (Sports Network) - Danny Espinosa's RBI single during a two-run seventh inning proved to be the difference as the Washington Nationals escaped with a 4-3 win over the St. Louis Cardinals in the finale of a four-game series on Sunday.

Kurt Suzuki smashed a solo home run and added an RBI base hit, while Ian Desmond chipped in with a run-scoring single for the NL East-leading Nationals, who have won four of their last five games.

Espinosa's single made a winner of Ryan Mattheus (5-1), who tossed 1 1/3 innings of relief behind starter Stephen Strasburg. Tyler Clippard picked up his 29th save of the year with a perfect ninth.

Strasburg pitched six scoreless innings with nine strikeouts and one walk. He allowed just two hits in a no-decision.

He is now 3 2/3 innings away from his limit of 160. Once he reaches that number, he could be shut down by the club for the remainder of the regular season.

09/02 17:04:57 ET