The Cubs tallied in the eighth against Jonathan Broxton on a two-run double by Baez. Castro then smacked a long hit off the center-field wall, but only made it to first base while sending Baez to third. It may have proved costly as Soler then drove in Baez from third on a single before Welington Castillo grounded into an inning-ending double play.
"He feels bad," Cubs manager Rick Renteria said of Castro, who returned from the bereavement list on Tuesday. "He knows. He's apologizing to everybody about not getting over there. He's got a lot of things on his mind, and he's out there doing the best he can.
"When a young man tells you he's made a mistake, it's very hard to do anything other than accept it. Quite frankly, there were a host of things prior to that, and part of that whole ballgame, that put us in the position we were in."
Baez nearly made up for the mistake with two outs and two on in the ninth, when he flied out to deep center.
"It sounded good," Renteria said.
"I had to take a couple of steps back, and I got a little scared; it sounded so loud and it was really high, but, the ball jumps off his bat no matter where he hits it to," Reds center fielder Billy Hamilton said. "I was just talking to [someone] about how his foul balls go up in the third deck every time he hits a foul ball off to the right. The guy has some power. And he had power coming in at him; all he had to do was touch it a little bit. But we got the win, and we did a good job."