May 23, 1936: OF Sammy Byrd becomes the only player in Reds history to hit a grand slam in the bottom of the 9th to overcome a 3 run deficit. The Reds trailed the Pirates, 3-0, entering the bottom of the 9th at Crosley Field. Cincinnati loaded the bases against Bucs hurler Bob Swift. Cy Blanton replaced Swift on the mound, and Byrd socked Blanton’s first pitch over the LF wall for the game winning grand slam.
When Byrd was with the Yankees (1929-1934) he acquired the nickname “Babe Ruth’s legs” because he was often used as a late inning defensive replacement for Ruth. Byrd was the best golfer ever to play in the big leagues. He won 23 professional tournaments.
All “Reds trivia” posts come from Greg Rhodes and John Snyder’s fabulous book, “Redleg Journal” (see link for purchasing) and are used with Greg’s permission.
Thanks again to Greg Rhodes for permission to use his material.
Comment: Did Dunn hit a grand slam to beat Cleveland earlier this year?

In answer to your question, that was a couple years ago, while The Redleg Journal goes up to 2000.
On June 30, 2006, Adam Dunn hit a walk-off grandslam in the bottom of the ninth to beat Cleveland 9-8.
(Also, I think that homerun may have been the “Can you believe it!!!” call by Marty, which got so much play in WLW promos and lead-ins…)
The thing that I remember even more about that game is how optimistic I was that they were really going to turn it on from there, but the exact opposite happened.
If I recall, right after that they went on the road and proceeded to fall right out of the race with a multitude of losses.