The Reds won Friday's opener when Jay Bruce belted a three-run homer in the eighth to power the Reds to a 5-3 decision.
Pinch-hitter Ramon Hernandez drew a one-out free pass in the eighth before Joey Votto was intentionally walked with two outs. Bruce then came to the plate and clobbered an 0-1 offering over the right-field wall.
The Padres took a 3-2 lead in the away eighth after Orlando Hudson scored on Logan Forsythe's single to center, but Josh Spence (0-1) was unable to keep Cincinnati from rallying in the home half and took the loss after giving up the game-winning home run.
Bill Bray (3-2) took home the win for the Reds after recording the final out in the eighth. Francisco Cordero picked up his 23rd save of the season after tossing a perfect ninth frame.
Bronson Arroyo started for the Reds and allowed two runs -- one earned -- on six hits over six frames.
Bailey, a 25-year-old Texan, is 2-0 in four career starts against the Padres with a 4.05 earned run average across 26 2/3 innings. He's walked five batters and struck out 20 against the Padres, while allowing 12 runs and 26 hits.
A four-time winner in 19 starts last season, Bailey has won three of his last four decisions to improve to 22-21 in 69 career outings.
He tossed eight innings of five-hit, one-run ball at Houston for a 5-1 win on Aug. 2, but lasted just three innings while being touched for five runs on six hits against Colorado six days later.
The Reds lost the game, 10-7, and are 3-7 in his last 10 starts.
For the Padres, Tim Stauffer can stay unbeaten in his sixth career outing against Cincinnati.
Like Bailey, a former first-round draft pick, the Portland, Maine native is 2-0 with a stingy 2.18 ERA across 20 2/3 innings over five appearances -- three starts.
The 29-year-old was a 3-0 winner over Los Angeles on Aug. 3 after allowing six hits in 6 1/3 scoreless innings.
A no-decision in San Diego's 9-8 loss to the New York Mets came five days later, when Stauffer allowed four runs on six hits in seven innings.
He is 3-4 in 12 road starts this season and the Padres are 5-5 in his last 10 overall outings.
Cincinnati took two of three from the Padres earlier in the year.