Kuchar, a nine-time winner on Tour, walked off the 18th hole at Sedgefield Country Club on Sunday, opting not to play his second shot.
With darkness looming over North Carolina, the 46-year-old rushed to finish his round before finding the left rough from the tee, leaving 212 yards to the pin.
But Kuchar said enough was enough and told Todd Lewis that he was “trying to set an example for Max [Greyserman],” who had earlier blown a four-shot lead.
“We were so far past when we should’ve stopped playing,” he said.
“We saw what Max did on hole 16; they should’ve blown the hole there. I feel bad, the poor kid should’ve won this tournament. By me not playing, it may show Max he has an important shot to hit.”