Chicago Cubs starting pitcher Travis Wood delivers against the Atlanta Braves during the first inning of a baseball game on Saturday, Sept. 21, 2013, in Chicago.

CHICAGO - Dioner Navarro hit a tiebreaking single in a three-run eighth inning, and the Chicago Cubs beat Atlanta 3-1 Saturday to keep the Braves on the brink of the NL East championship.

Atlanta's magic number remained at one to clinch its first division title since 2005. Second-place Washington hosted Miami later Saturday.

Starlin Casto singled off Kris Medlen with one out in the eighth, pinch-hitter Donnie Murphy singled against Scott Downs (4-4) and Anthony Rizzo hit a tying double down the left-field line.

Navarro singled in the go-ahead run against David Carpenter, and Nate Schierholtz added a sacrifice fly.

Carlos Villanueva (7-8) got three outs in the eighth, and Pedro Strop finished for his first save in four chances.