The Cubbies winning ways did not stretch to 12 wins in 13 games Wednesday.
Chicago fell 6-0 to the Nationals in Washington D.C.
Rich Hill struggled on the mound, giving up an early home run to Ryan Zimmerman. Later in the 5th, Hill gave up a grand slam to Dimitri Young.
The loss drops the Cubs to 42-41. They remain 5.5 games back of the Brewers for first place in the NL Central. Milwaukee lost at Pittsburgh 5-3.
Chicago completes its 4-game series with the Nationals Thursday Night at 7.