Williams had objected to wearing a BNZ and Investec logo on his collar as his Muslim religious beliefs don't allow him to promote banks, alcohol brands and gambling sponsors.
Instead, Williams' jersey last night the symbol of children's charity Plunket on its collar.
Plunket is supported by BNZ, which suggested the community organisation fill the space on the collar of Williams' playing jersey.
"I want to say that I am deeply grateful to BNZ for allowing me to play with a clear mind," Williams told SMH.
"They have been more than understanding. Their level of respect towards me is something I admire and their idea to back a group [Plunket] that helps kids and their parents is a great one. The person who thought of that deserves a huge amount of credit."
BNZ chief executive Anthony Healy said on Thursday, "We are delighted that Sonny Bill has agreed to give the space, previously allocated to BNZ, to another of our core sponsorships, Plunket, who provide a vital support service for children and new parents".
Plunket chief executive Amanda Malu described Williams' decision a "real honour".
"We're thrilled such a high-profile Kiwi dad and role model is getting behind Plunket," she said.
"A lot of families will be watching this season and we're proud to be there supporting Sonny Bill as a dedicated father and role model for Kiwi kids.
"Sonny Bill is helping Plunket remind parents that our services are here to support mums as well as dads."
Williams says his stance is legitimate.
"I was not making a stance to be a troublemaker or attention seeker - anyone who knows me knows that's not part of my make up. It's not the person I am or want to be, but I will stand up for my views every day of the week."