DeSclafani (5-5, 3.48) gave up three runs on four hits in the fourth inning to cool off his hot start and give him his first loss in his last six starts. The troublesome inning began with a leadoff home run by Derek Dietrich. Christian Yelich followed with a double and Giancarlo Stanton singled to put runners on the corner. Yelich would score on a fielder's choice ground out and J.T. Realmuto would double to score Stanton.
"I just missed, I fell behind in counts and made a mistake on a pitch to Dietrich," DeSclafani said. "They just put some good swings on the ball. It's going to happen sometimes, that's baseball. Definitely want to try to limit, try not to put up a crooked number that inning."
DeSclafani walked back-to-back Marlins in the fifth inning -- his last frame. DeSclafani threw only 86 pitches after throwing more than 100 in his last three starts.
"Not so much that they are out there hitting a bunch of great pitcher's pitches," Reds manager Bryan Price said of DeSclafani's fourth- and fifth-inning struggles. "They take advantage of the mistakes that the pitcher makes and he had some elevation mistakes, a slider backed up a couple of times on him. He was able to get through that with the three runs and walked a couple of guys the next inning. Just didn't look like he was back on top of his game."
The former Marlin wasn't only facing his old team, but also his former teammate and roommate at Double-A Jacksonville, Justin Nicolino. The 23-year-old lefty made his Major League debut on Saturday for the Marlins after scheduled starter Tom Koehler was scratched with neck stiffness.
Nicolino provided seven scoreless innings for the Marlins, giving up only four hits and two walks in his first career start and victory. However, one of those hits came off the bat of DeSclafani in the third inning when center fielder Marcell Ozuna slipped on the play.
DeSclafani, who also got a strikeout against Nicolino in the third inning, said it appeared his former roommate was upset with the single as he stood at first base.
"He was kind of mad at me at that," DeSclafani said. "I just swung, happened to square up and I think it would have been a routine out if Ozuna [didn't fall]. I don't know what happened out there, I just kind of saw the ball drop and got past him. I got lucky, but he was a little mad at me. He stared at me while I was at first base."
Robert Bondy is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.