CHICAGO -- At a time of the season when it matters the most, the Reds let yet another game -- and another series -- get away.

A three-run home run by Jason Heyward in the bottom of the 10th inning doomed the Reds to a 4-1 loss to the Cubs on Wednesday at Wrigley Field. It was Cincinnati's fifth consecutive series loss as it dropped two of three games to Chicago.

"We just have to keep playing," Reds manager David Bell said. "Obviously, a tough loss tonight. They all are. But we have a lot left ahead of us. We’ll put it behind us and move forward.”

There were consequences for losing. A Padres win over the Angels meant the Reds (74-67) fell one game back for the second National League Wild Card spot. The Cardinals also won and sit 3 1/2 games back. Cincinnati and St. Louis will meet again Friday to open a three-game series at Busch Stadium with a lot on the line. The only break for the Reds on Wednesday was that the Phillies also lost and sit three games back.

Some strong pitching was wasted. Reds starter Vladimir Gutierrez allowed one earned run and two hits over five innings with two walks and six strikeouts. Until the 10th inning, the bullpen was brilliant with four perfect innings combined among Tony Santillan in the sixth and seventh, Luis Cessa in the eighth and Mychal Givens in the ninth.

"Between Guti and those three guys, they certainly gave us a chance to win the game," Bell said.

In the bottom of the first inning, Ian Happ's drive to right field on Gutierrez's 0-1 pitch gave him his seventh homer this season vs. the Reds and Chicago a 1-0 lead.

"In that at-bat, the catcher asked for a changeup right there," Gutierrez said via translator Jorge Merlos. "I shook him off and I wanted the fastball right there, and I guess maybe the batter right there was waiting for a fastball. But if I would have thrown a changeup, it would have been different, but it’s just how it is."

After Willson Contreras followed Happ with a fly ball to center field, Cubs hitters did not get another ball out of the infield before the 10th inning. After Sergio Alcántara's bunt single with two outs in the second inning, no Reds pitcher gave up another hit -- also until the 10th.

Because Givens pitched Tuesday, he was not given a second inning of work. Michael Lorenzen pitched the previous two games and did not fare well. Lucas Sims had pitched two of the previous four games, but he also warmed up in the two games he didn't appear in. Therefore, Brad Brach was given the 10th inning.

"He was not an option to pitch an inning tonight," Bell said of Sims. "Brad has been there many, many times. He has done it for us. It’s only his second time out [back from the injured list]. He’s still going to get more comfortable and will get back to where he was before his injury.”

Brach faced only two batters. The first batter, Patrick Wisdom, hit a leadoff single that moved the automatic runner to third base. Cincinnati brought right fielder Nick Castellanos in as a fifth infielder to prevent a Heyward grounder from getting through.

It wouldn't matter, however. Heyward crushed a 1-1 slider from Brach to right field for a no-doubt walk-off homer.

"It was a good series for us," Cubs acting manager Andy Green said. "It was good, clean baseball for all three days. We defended the field well. We pitched well. And we got some key hits. That's a fun way to end a baseball game, with a guy as good as J-Hey hitting a baseball like that."

Against Alec Mills in the top of the fourth with two outs, Joey Votto lifted a 3-2 pitch to left-center field for a solo homer. It was Votto's team-leading 29th homer of the season and it snapped his season-high 16-game streak without clearing the fences.

For Votto, who turns 38 on Friday, it also gave him 324 career home runs to tie Frank Robinson for second on the franchise's all-time list.

It wasn't a good series, overall, for an offense that batted .222 with eight runs in the three games. In the last 15 games, the team is batting .227 while series were dropped to the non-contending Marlins, Tigers and Cubs, along with the contending Brewers and Cardinals.

"We’re going to come back. We’re going to look towards St. Louis right now and try to see if we could get more wins," Gutierrez said. "Obviously, we never want to lose, but we’re always trying to win. These are games that hurt a little bit, too."