On May 26, 1920, a bonheaded play by Reds outfielder Pat Duncan led to Rogers Hornsby tacking on an insurance run during the eighth inning of a 10-8 Cardinals win at Robison Field in St. Louis. The game was a seesaw battle that had the Cards up 8-5 heading into the top of the eighth. However, the lead disappeared with the Reds plating three runs to tie it up. Milt Stock picked up his fourth hit of the day with a triple in the bottom half of the inning, then Hornsby came up with a single to left to bring Stock into score the go ahead run. Duncan then began trotting off the field thinking that the it was ninth inning and Hornsby's single was a walk off winner. Hornsby wheeled around the bases and scored before Duncan could recover from the miscue. While some accounts credited Hornsby with an inside-the-park home run, that was not the case, as Duncan was charged with an error, while Rogers was given a single in the official box score. I would imagine that Duncan felt like a bit of an ass after this one.
Check out the box score here: http://www.baseball-reference.com/boxes/SLN/SLN192005260.shtml