WASHINGTON, Aug. 25 (UPI) -- Ryan Dempster allowed two hits and struck out eight over seven innings Wednesday, leading the Chicago Cubs to a 4-0 blanking of Washington.
The Cubs completed a three-game sweep of the Nationals, who have dropped four in a row overall.
Dempster (12-8) walked one and gave up a one-out, infield single to Wil Nieves in the fourth innings and a one-out base hit to pitcher Jason Marquis in the sixth.
Andrew Cashner and Carlos Marmol worked an inning each to complete the shutout. They both gave up a hit.
The game was scoreless through seven innings but Tyler Colvin drew a walk off Marquis (0-7), stole second and scored on Starlin Castro's one-out double. After Marlon Byrd struck out, Aramis Ramirez hit his 20th homer of the season.
Alfonso Soriano added a home run in the ninth, his 21st.
Marquis has lost all of his starts this season after having had a winning record in each of the last three years.