Phillip Ervin sent them in the other direction.
"There is nothing like it," Ervin said. "It's a great feeling. I thought I hit it good enough. I saw Harper go back on it. The wind just pushed it out. I was just trying to get on base, but everyone wanted to get out of here."
Ervin's sixth home run this season and the second game-ending homer of his career gave the Reds their second straight win and a four-game split.
"Obviously, it's a super disappointing loss," Phillies manager Gabe Kapler said. "Our path to success is going to be through our offense and having big innings, and we weren't able to do that in these games."
Realmuto tripled in the fourth and tied the game in the eighth against Robert Stephenson when he led off with his 21st homer. The catcher also stopped a seventh-inning rally attempt by nabbing Jose Peraza off second base with a pinpoint throw.
Philadelphia rallied from a 5-0 deficit to tie the score on Wednesday, then lost 8-5.
"It's definitely frustrating," Realmuto said. "We won the first two games and we had a great chance to win three out of four, and we're thinking maybe we can sweep the series. Everybody in the dugout felt the momentum. We put ourselves in position to win the game, but the offense didn't get it done."
"We've still got plenty of time, but we have to turn it around quickly," he added. "We've got some important games coming up."
Center fielder Adam Haseley also had two hits for the Phillies. Harper was 1 for 4 with a bunt single, a walk and two stolen bases
Vincent was the ninth pitcher for the Phillies. Starter Jason Vargas gave up two runs and four hits in 5 1/3 innings.
Realmuto missed a home run by about a foot with a line drive off the top of the left-field wall leading off the fourth, then scored on Rhys Hoskins' double.
Jose Iglesias hit a two-run homer in the sixth off Vargas and Eugenio Suarez greeted former teammate Jared Hughes with his 41st homer, an opposite-field drive to right-center that just cleared the fence on Hughes' first pitch. Philadelphia claimed Hughes on waivers from the Reds on Aug. 15.
Cincinnati's Michael Lorenzen, who regularly played the outfield when he wasn't pitching in college, made his first big league start in center field and went 1 for 3 with a walk. On Wednesday, he became the first player to get a victory, hit a homer and play outfield in the same game since Babe Ruth in 1921. Lorenzen, Logan Morrison, Jay Bruce and Jose Iglesias homered Wednesday, the first game since 1900 in which four players not in the starting lineup for either team went deep, according to the Elias Sports Bureau.
Phillies INF Maikel Franco was recalled from Triple-A Lehigh Valley.
Phillies: LF Corey Dickerson was 0 for 5, a day after leaving in the fifth inning because of a sore left foot.
Reds: OF Jesse Winker is expected to start swinging a bat in the next couple of days. Winker hasn't played since Aug. 18 because of a cervical strain.
Phillies: RHP Zach Eflin (8-11) is 1-1 with a 9.00 ERA in two starts against the Mets this season going into Friday's game at New York
Reds: RHP Tyler Mahle (2-10), who starts Friday against Arizona, has left games this season with nine runners on base, and they all scored.
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