KANSAS CITY -- When Brady Singer exited Wednesday’s game after facing one batter in the seventh inning, he walked off the mound to a round of fist bumps from his teammates and a loud ovation from the crowd at Kauffman Stadium. After six dominant innings from Singer, the Royals had their most reliable reliever coming to the mound.

In a span of three batters, the Reds then took the lead off right-hander Scott Barlow and -- after a one-hour, 12-minute rain delay -- continued to pile on against the back end of the Royals’ bullpen to hand Kansas City a 5-2 loss. After a wild comeback win Tuesday night, the Royals dropped the series and have lost 12 of their past 15 games.

• Box score

“We put ourselves in a position to win that game,” manager Mike Matheny said. “That’s just a game we felt slip away when we’ve got a well-rested ‘pen, we were able to give Scott some time to come in. We’ve asked a lot of a few of those guys in that ‘pen, and they’ve been really good. Today was one that slipped through our hands.”

Up until that point, the Royals looked on their way to a series win. Singer was dominant for six scoreless innings, allowing just four hits, one walk and two hit batters while striking out six. There have been times this season when Singer has had trouble commanding his sinker, which leads to his slider not playing off of it like it should. And with a two-pitch mix, that can lead to lopsided scores and short starts.

But when Singer is commanding his sinker like he did Wednesday, he’s elite. He registered nine whiffs and got 19 called strikes, and the contact he did get was weak or hit to a well-positioned defense.

“That’s something we’ve talked about with my whole arsenal this whole entire year is just trusting my stuff,” Singer said. “I get into these predicaments when I get ahead in the count, 0-2 or 1-2, and I feel like I go away from my strengths there and not trust as much as I should. That was something I felt like I did a lot better today: Trust what I have.”

The Royals had a two-run lead on Reds starter Sonny Gray, so as soon as Singer faced traffic in the seventh inning after Tucker Barnhart’s single, Matheny turned to Barlow, who was rested and has gotten Kansas City out of these situations all season as one of the best relievers in the American League.

“He’s been so good all year,” Matheny said. “We’d take him against anybody in any situation. We haven’t seen many days like that for Scott. They’re going to happen. It’s unfortunate because we’re in the right spot of the game where we want him in there.”

But Barlow’s breaking balls weren’t sharp Wednesday, and with two strikes on Shogo Akiyama, the Reds’ center fielder hit a potential double-play grounder that was out of reach of third baseman Hunter Dozier’s diving attempt.

Barlow got to two strikes against Mike Freeman before he laced a ball into left field to put the Reds on the board. And then with two strikes on Jonathan India, Barlow misplaced a curveball that India roped for a double to score two and take the lead.

“Failed at execution, especially with two strikes,” Barlow said. “Watching Brady pitch today, he was awesome. He was dialed in. Coming in with a runner on first, nobody out, thought I had a good chance of getting out of that. Unfortunately I didn’t. Definitely frustrating. Especially what [Singer] did all game.”

A day after mounting a five-run comeback against the Reds’ bullpen, the Royals’ offense couldn’t do so again after the rain delay. Two walks and a single loaded the bases with two outs in the eighth inning for Dozier, who belted a high fly ball 373 feet to left-center field. In 13 ballparks, it would have been a grand slam.

At Kauffman Stadium, it was a flyout to the warning track.

“As soon as he hit it, I thought it was gone,” Matheny said. “The ball didn’t carry very much this series for some reason, I don’t know if it was after the rain or humidity or whatever reason. It came off the bat pretty good, the trajectory was right. We were probably wishing it out of the ballpark as much as anything.

“It was so close to being what we were looking for.”