Alex Avila capped Chicago's three-run 10th inning with a two-run single, and the Cubs swept the Toronto Blue Jays with a wild 6-5 victory on Sunday.
What are the remaining schedules, certainties and X factors for the contenders? Here's a closer look.
The Cubs have one of the best defensive right fielders in baseball in Jason Heyward, but he can't carry the group all by himself.
The Bears' rookie made enough plays Saturday against the Cardinals to stake his claim as the starting quarterback.
Consistent Davis ties Cubs record
With Saturday's outing, Wade Davis has successfully converted all of his save attempts since joining the Cubs this year, and his 26 straight saves without a blown attempt tied a Cubs record set by Ryan Dempster over the 2005-06 seasons. (Elias Sports Bureau)
Mike Glennon turned in a pedestrian performance on Saturday, with a touchdown and an interception, as the Bears scored a 24-23 victory at Arizona.
Rookie Ian Happ hit his 18th home run, Jose Quintana pitched six effective innings and the Chicago Cubs beat the Toronto Blue Jays 4-3 Saturday to keep up their success against AL opponents.
The Chicago Cubs have claimed veteran catcher Rene Rivera off waivers from the New York Mets.
Jake Arrieta pitched into the seventh inning and allowed a run, Javier Baez homered and drove in three runs and the Chicago Cubs beat the Toronto Blue Jays 7-4 on Friday.
The Chicago Cubs have placed ace left-hander Jon Lester on the 10-day disabled list with left lat tightness and shoulder fatigue.
Before conversations with Diamondbacks manager Torey Lovullo and Royals director of pro scouting Gene Watson, Pedro Gomez chats with Bob Nightengale about the Cubs facing another injury, the NL wild-card race, the phenomenal job done by Mike Scioscia this season and more.
Josh Macri recaps all of Thursday's MLB action, including a potential damaging blow for the Cubs, a Yankee sweep, a big day for Ender Inciarte and much more.