Maybe it was the early holiday start (12:10 p.m.)?
Could it have been the 13-inning marathon against the Giants that ended Sunday evening?
Or maybe the credit goes to Brewers starter Zach Davies.
Whatever the reason, the Cubs got out to a slow start offensively on Labor Day Monday, but turned it on late to coast to a 7-2 victory over the Milwaukee Brewers in front of 43,662 (mostly Cubs) fans at Miller Park.
The Cubs didn't score until the sixth when Jorge Soler lifted a broken-bat single into shallow left-center to bring home Tommy La Stella.
In the seventh, Chris Coghlan notched a two-out RBI hit and then came around to score when La Stella's single bounced out of Brewers second baseman Scooter Gennett's glove and into shallow right field.
The Cubs really broke the game open in the eighth inning with Heyward driving in a run on a fielder's choice (and another Brewers error), Javy Baez scoring Addison Russell with a perfectly-executed bunt and then Coghlan's two-run single.
"Everybody was contributing," Joe Maddon said. "There were a lot of good at-bats. Their guy's good. Davies, I have a lot of respect for him, He's a good, young pitcher.
"... One of our goals is to score first, but we've been able to overcome early deficits and we've got that strong believability that we can. That's a bit part of our recent success."
Coghlan - who was 2-for-2 with three RBI off the bench - echoed his manager's thoughts about the Cubs' late comebacks.
"That's the belief," Coghlan said. "If we don't do it right out of the game, then our belief is always that we'll do it before it's over. That's why it's tough to shut us out and to keep us down.
"Lately, it seems like we've been doing it later in games, which I mean that's what you gotta do to win. You gotta do it in the beginning - punch them in the mouth - and if you don't, then you gotta do it late and steal one from 'em.
"That's what we've done and I think that's a reason why we win so many games."
Kyle Hendricks did what he does best - saved the bullpen after a crazy game the day before.
For the fourth straight time in such situations, Hendricks picked up a victory, surrendering only one run in six innings to lower his MLB-leading ERA to 2.07.
"After really awkward games, he has really picked us up," Maddon said. "That's just who he is. He normally gets you deeply into the game.
"... You pretty much have an idea what you're gonna get when he goes out there - strike-throwing, they gotta put the ball in play, they gotta move it. He normally does not get himself into trouble."
Hendricks' only real mistake was a homer by Chris Carter to lead off the second inning and the Cubs' potential Cy Young candidate improved to 14-7 on the season.
"I don't think there's any doubt [Hendricks is a Cy Young candidate]," catcher Miguel Montero said. "Is there anybody having a better year so far as him? I mean, he probably doesn't have as many innings as other guys, but that's not his fault, put it that way.
"He gives you his best every time he goes out there. The way he's been pitching, I don't see anybody that's been pitching as good.
"He's a complete pitcher. He knows he needs to pitch in order for him to get away with stuff, he needs to be smart about it and he needs to locate his pitches."
For his part, Hendricks shrugged off any talk of individual awards, deflecting to talk about his teammates.
"Personal accolades are something that just comes along with playing well," Hendricks said. "We're all here for staying healthy in September, getting ready for October and do it as a team."