Brett Tomko (10-7), who held Florida without a hit until the fifth inning, allowed two runs and five hits in seven innings, striking out four and walking three.
The loss was the Marlins' 71st of the year, one more than their total last season when they won the World Series.
Gabe White pitched two perfect innings for his first save.
Matt Mantei (3-1), who relieved starter Jesus Sanchez, took the loss. Sanchez allowed two runs and seven hits in six-plus innings.
After Sanchez walked Tomko to start the seventh, Mantei came on. With one out Chris Stynes walked, and one out later Young doubled him and Tomko home before getting thrown out trying to stretch it into a triple.
Cincinnati jumped in front in the first inning when Barry Larkin singled, moved to second on a walk to Young, and scored on Eduardo Perez's single.
Florida tied the game 1-1 in the fifth when Dave Berg doubled home Craig Counsell, who had singled.
Florida took the lead in the sixth as Edgar Renteria led off with a walk. One out later, Cliff Floyd singled on a hit-and-run to send Renteria to third. Counsell then doubled home Renteria.
©1998 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed