The Cubs rallied for three runs off Mat Latos to make it a one-run game in the fifth inning, helped when Reds center fielder Shin-Soo Choo and second baseman Brandon Phillips collided trying to catch Alfonso Soriano's short fly.
Latos (3-0) extended his scoreless streak to 21 innings, tying a career high, but didn't pitch past the fifth inning for the first time in seven starts this season. He struck out six and walked three.
J.J. Hooverearned his second save.
Edwin Jackson (0-5) struggled again for the Cubs, allowing four runs and eight hits in five innings.