Cincinnati had been unable to convert chances in the top of the ninth, 10th and 11th innings after it stranded a combined five runners on base in the last three innings of a 2-1 loss to the Cubs on Sunday.
"A real frustrating game," Reds manager Bryan Price said. "It was just really a chance to have a better finale with this series. We had a lot of chances, especially late in the game.
"We had more opportunities late in the game to score than they did … and we didn't get it done."
After falling to the Cubs in the 11th inning on a walk-off single, the Reds dropped three in a four-game series after they entered on a four-game winning streak.
The Reds put 12 runners in scoring position Sunday, compared with Chicago's five runners in scoring position.
"It just didn't happen," said Reds third baseman Todd Frazier. "We had a lot of energy, you look at the positive, guys working their tails off that are coming in. We just didn't get it done. It's a close game the whole way, great pitching the whole way.
"One guy just stepped up," Frazier said. "There's nothing you can really do."
In the ninth, Cincinnati loaded the bases with its first three batters, nearly scoring Joey Votto on a double from Frazier. But a throw from Cubs center fielder Dexter Fowler froze Votto at third base and allowed reliever Jason Motte to escape the threat. Brayan Pena flied out, Eugenio Suarez struck out and Kristopher Negron lined out to end the threat.
And in the 10th, center fielder Billy Hamilton recorded his fourth and fifth steals of the game to reach third base, but this time it was Zac Rosscup who closed the door after Votto lined out to left.
In the 11th, Jay Bruce and Pena both reached, but it was reliever Brian Schlitter who forced two groundouts -- one each from Suarez and Negron -- to escape.
"It was a tough one to lose," Price said. "Two starters [Anthony DeSclafani for the Reds and Jon Lester for the Cubs] that gave both teams a great chance, but we certainly had a lot of chances late in the game to at least take the lead in that game. And we just couldn't get there."