Charles Kane pleaded guilty to aggravated manslaughter in the 2010 death of Elijah Ulbrich. The 37-year-old will face 15 years in prison when he's sentenced in May instead of 30 had he been convicted of murder.
The plea came during a pretrial hearing on Tuesday.
Cape May County prosecutors said the boy's mother had left her child with the Lower Township resident while she ran some errands.
Kane told the court he was upset that the boy had wet his pants and he pushed the child against the refrigerator door.
Outside of court, the child's parents told The Press of Atlantic City the 15-year sentence wasn't long enough.
Information from: The Press of Atlantic City