Mike Montgomery continues to dominate the club that drafted him out of high school.
Montgomery allowed five hits over six-plus innings, David Bote drove in a career-high three runs and the Chicago Cubs beat the Kansas City Royals 5-0 Tuesday night.
The Cubs upped their NL Central lead to 2 ½ games over second-place Milwaukee, which lost in San Diego.
Montgomery (4-4), who the Royals drafted in the first round in 2008, picked up his first win since June 29. Montgomery is 3-0 with a 0.40 ERA in four appearances against the Royals.
Bote's first career triple with two out in the first scored Ben Zobrist and Jason Heyward. His fifth inning single scored Javier Baez.
Victor Caratini, who led off the inning with a single, scored on Zobrist's sacrifice fly. Zobrist left in the bottom of the inning with left hip tightness, but will likely play Wednesday.
Ian Happ's sacrifice fly in the eighth scored Bote with the final run.
Keller (4-5) was removed after six innings, allowing four runs on seven hits and three walks.
The Royals had only one runner past second base, when Adalberto Mondesi swiped third in the seventh.
The Royals have lost six straight and are 14-43 since May 30. They are tied with Baltimore for the worst record, 34-79, in the majors.
LHP Jose Quintana, who is 3-9 versus the Royals, will start the series finale.