On April 10, 1996, at about 1245 eastern daylight time, a Piper PA25-235, N8510L, sustained substantial damage when it nosed over during the landing roll at Caesar Creek Gliderport, in Waynesville, Ohio. The pilot, the sole occupant, received minor injuries. Visual meteorological conditions prevailed for the local flight, and no flight plan was filed. The glider tow flight was conducted under 14 CFR Part 91. The flight originated from Waynesville, Ohio, at 1230 eastern daylight time. The pilot stated that he took off with a glider in tow, and the glider "...got off at 2000 [feet above ground level] AGL." The pilot reported that he returned to land, made a normal approach, and landed "...with a slight quartering tailwind." He stated that when the airplane encountered a wet spot on grass runway, the tail came up, the airplane nosed over, and came to rest inverted. The pilot reported that he landed on runway 9, and the winds were out of 300 degrees at 10 knots. The Federal Aviation Administration (FAA) Inspector stated that the grass runway appeared to be well maintained and mowed. She also stated that the soft, wet portion of the field was not visually evident except where the accident airplane tires sank into the grass.