PITTSBURGH, Sept. 5 (UPI) -- Ryan Zimmerman collected a pair of RBI singles and drove in four runs Sunday in the Washington Nationals' 8-1 rout of Pittsburgh.

Adam Dunn contributed a solo homer and drove in two runs for Washington, which won its fifth in eight games and took the rubber match of a three-game series at PNC Park.

Jason Marquis (2-7) got the victory after going six innings. He yielded one run on six hits, striking out two without issuing a walk.

Pittsburgh was led by Pedro Alvarez, who socked a homer. Starter Charlie Morton (1-11) survived only 3 2/3 innings, surrendering six runs (two earned) on eight hits with a pair of walks.