Kirk Saarloos' outing is over after the Reds right-hander failed to record an out in the first inning.
The Pirates led 5-0 with runners on first and second when Reds manager Jerry Narron pulled Saarloos and brought in Victor Santos from the bullpen.
Saarloos faced seven batters and allowed three singles, one double, a three-run home run by Jason Bay on a full count and walked two Pirates on full counts. He threw 38 pitches, 24 for strikes.
The first batter Santos faced, Pirates shortstop Jack Wilson, grounded into a double play. The second batter he faced, pitcher Zach Duke, grounded out.
The Reds have now been outscored 50-23 in the first inning this season and 16-1 in the first inning during this homestand.