"We just didn't do our job. We haven't been doing our job in a while," Reds second baseman Brandon Phillips said.
The only two runs in the game came from Logan Schafer, who hit his first Major League home run off Tony Cingrani in the fifth inning. Schafer wasn't even in the original lineup, but was a last-minute substitute when right fielder Norichika Aoki was scratched with an injury.
And the only Reds hitter seemingly with momentum, Chris Heisey, was knocked out in the second inning when hit on the left elbow by a 95-mph Peralta fastball. X-rays were negative.
What is really negative are the four losses in the Reds' last five games -- with the opponents being an unheralded Mariners club and a last-place Brewers team that has a 37-52 record. Losing back-to-back games to Milwaukee also means the Reds have now dropped five of their last six series. Before this week, the Reds had taken five of six in the season series.
"A lot of guys in our lineup are banged up," Phillips said. "We have a lot of people playing with injuries. Once everybody is on the same page and gets it going, and everybody is healthy, we'll be all right. We're not panicking. We'll be all right. That's how I see it. I'm not really trippin'. I know we're not winning. Nobody is really hitting the ball. Nobody is really standing out. Something has to turn up."
Cingrani gave up two runs on just three hits over seven innings with two walks and 10 strikeouts. Still, it wasn't enough.
The game was scoreless until the fifth inning. Cingrani walked leadoff batter Martin Maldonado. On a first-pitch fastball to the next batter, Schafer hit a two-run homer into the right-field seats.
"Cingrani actually threw a better game [than Peralta]," Reds manager Dusty Baker said. "He had more strikeouts. There was only one left-handed hitter in the lineup. The one left-handed hitter hits a home run, his first home run. When you're not going too good, these kinds of things happen."
"Two mistakes. Walking Maldonado after being 0-2 and the first pitch to Schafer. I was trying to get ahead of him and he jumps me," Cingrani said. "I did my job. It's frustrating you can't get a win, but it's a game."
Peralta, who came in 5-9 with a 5.27 ERA, had all he needed to win from there.
"I've been thinking about it all my career, like, 'When am I going to throw a complete game?'" Peralta said. "The shutout was a blessing for me."
Shin-Soo Choo led off the game with a single up the middle against Peralta. Choo was promptly erased on a double play when Zack Cozart lined sharply to first base behind the runner.
Cincinnati didn't get another hit until there were two outs in the seventh, and that didn't end well, either. Derrick Robinson, who replaced Heisey, hit a triple to left field. As Jeff Bianchi bobbled the ball and made a late cutoff throw, Robinson was waved around third base by coach Chris Speier.
The throw to the plate from shortstop Jean Segura was perfect. The head-first sliding Robinson was called out by umpire Tim Welke on a very close play. On television replay, Robinson appeared to be safe with his hand on the plate ahead of a tag. Baker did not argue the call.
"You get the replay after. It's easy afterwards," Baker said. "Where we were, it looked like he blocked the plate on him. You guys saw it better than we did."
The Reds' third hit came when Jack Hannahan led off the eighth with a single to center field. Hannahan, too, was erased when pinch-hitter Xavier Paul bounced to second base for an inning-ending double play.
With this latest defeat, the Reds have fallen to five games behind the first-place Cardinals in the National League Central.
"It just takes one game for us to get it going," Phillips said. "Today was just another day. Hopefully tomorrow, we can get another spark, get something going."