The 25-year-old said he never considered leaving the Tshwane outfit even after being made aware of interest from the Soweto giants, saying the club has been too good to him.
Williams said the fact that he plays regurlaly and continues to win trophies with Matsatsantsa means that they also one of the big teams in the league.
He added that he wouldn't have risked leaving the club when he had no guarantees that he would enjoy the same amount of game time he's been getting at United.
"Although Pirates wanted me, SuperSport United is my home. They have always been good to me since day one. We're always challenging for titles and that means I'm also playing for a big team. So, there was no need to leave the team," Williams told the media.
"As we speak, we are in the quarter-finals of the Caf Confederation Cup. This team is going places. SuperSport is like my family. My family is also happy that I'm still playing for SuperSport," said the South Africa international.
"I'm a regular and I'm winning trophies. So, why should I go to another team when I don't even know if I would play? That's why I stayed at SuperSport," he added.