Cubs 7, Nationals 2: John Baker tied a career high with four RBIs and Jason Hammel pitched effectively into the seventh inning as host Chicago took a 2-0 lead in the four-game series.

Baker collected his first three-hit game of the season and Ryan Sweeney added two hits and two RBIs as the Cubs racked up 13 hits. Hammel (7-5) struck out six while allowing two runs and five hits over 6 1/3 innings to snap a four-start winless streak.

Adam LaRoche homered among two hits and Anthony Rendon added a pair of hits for the Nationals, who have lost three straight. Washington starter Tanner Roark (7-5), who had won his previous four starts, was tagged for four runs and a season-high 10 hits over six innings.

Ryan Zimmerman put the Nationals on top with an RBI double in the second, but Chicago answered in the bottom of the inning, taking the lead on back-to-back RBI singles from Baker and Darwin Barney. LaRoche's line-drive shot to right leading off the fourth tied it at 2 before Sweeney's two-run single broke the tie in the bottom of the frame.

The Cubs loaded the bases in the seventh against Jerry Blevins, who struck out Chris Coghlan to get within an out of getting out of the inning before Baker ripped a bases-clearing double into the right-field corner to break it open. The Nationals had two on in the eighth, but Wesley Wright worked out of the jam and Justin Grimm pitched a perfect ninth to seal it.

GAME NOTEBOOK: Hammel improved to 7-0 in nine career starts against the Nationals. … Washington has scored a total of 25 runs over its past nine games, going 4-5 over that span. … The teams play a scheduled split doubleheader to wrap up the series Saturday.