Billy Hamilton knocked in the winning run with a broken-bat single in the bottom of the ninth as host Cincinnati rallied from a 5-0 deficit to finish a sweep of the day-night doubleheader.
Jay Bruce drove in two runs, including the tying run on an RBI double in the eighth, and Zack Cozart had a pair of hits for the Reds, who have won the first three games of the five-game series. Logan Ondrusek (3-2) pitched two scoreless innings in relief to earn the win.
Chris Coghlan, Anthony Rizzo and Mike Olt all homered for the Cubs, who have lost five straight. Tsuyoshi Wade allowed one unearned run and five hits in five innings in his major-league debut and was in line for the win before the Reds rallied against Chicago's bullpen for their biggest comeback win of the year.
Coghlan's second blast of the doubleheader staked the Cubs to a 2-0 lead in the second, Rizzo added a solo shot in the third and Olt hit a two-run bomb later in the inning to make it 5-0. Hamilton got the Reds on the board with a sacrifice fly in the fifth and Bruce's RBI groundout made it 5-2 in the sixth.
The Reds loaded the bases with no outs in the seventh and plated runs when Devin Mesoraco grounded into a double play and Hamilton tripled home a run, and Bruce doubled in the tying run an inning later. Brayan Pena led off the ninth with a bloop single down the left-field line, Mesoraco's single moved pinch-runner Mike Leake to third and Hamilton slapped a soft liner to left off Hector Rondon (1-3) to end it.
GAME NOTEBOOK: The start of the game was delayed 35 minutes because of rain. … Coghlan is the first Cubs player to homer in both ends of a doubleheader since Alfonso Soriano on Sept. 15, 2007. … Reds relievers worked nine scoreless innings in the doubleheader, including 6 1/3 in relief of rookie David Holmberg, who allowed five runs and seven hits in 2 2/3 innings in the nightcap.