This entwining of man and club produced, in Williams' case, a career with influence far beyond the training "tan" at Ponsonby's old clubrooms in Blake St.
His exploits as a player are known throughout the world. But as a coach, he was pivotal in turning Auckland rugby around in the 1980s as he and Maurice Trapp built on the foundations laid by John Hart.
Williams, with his Ponsonby mate and Samoan captain Peter Fatialofa, helped orchestrate Manu Samoa's stunning World Cup debut in 1991 and beyond. What a career.
"It's the end of an era in my life - it signals the end of my really active rugby career, although I'm not leaving the club by any stretch," says Williams, as we settle into chairs at the Western Springs clubrooms.
This journey began when the 10-year-old Williams - his famous sidestep already under development - followed brothers Ces and Ken into the black and blue hoops.
Before his teens were over, Williams had added to Ponsonby's reputation for producing All Blacks via his storming performances in the three-quarters on the All Blacks' 1970 tour of South Africa when he launched his test career with career-best form. The sight of those thunderous thighs propelling him over the hard grounds will never be forgotten.
His sudden emergence was also the signpost to a Pacific Islands rugby revolution, although his heritage is an unusual melting pot.
His maternal grandfather was South African, an agricultural official heading to the Bahamas who somehow ended up in Rarotonga where he married Williams' grandmother, a Samoan. On the other side, his grandparents are Australian and Samoan.
Williams was an Auckland inner city kid of the 1950s and 60s, from O'Neill St, off Ponsonby Rd. His memories are an idyll, and include racing home-made trolleys, climbing trees, secret clubs below the floorboards, the arrival of TV in some homes, playing the guitar ... and sport.
He was a junior for Ponsonby league where an Englishman he knew as Yorkie taught the kids to sidestep on Clarence St fields. This gave Williams, a natural athletic talent, a serious weapon, one he unleashed to the sort of rhythms he equates to an athlete performing the triple jump.
Williams changed direction as sharply as anyone who has played the game, whereas his devotion to Ponsonby is straight and true.
"Two words sum him up - loyal and humble," says Kevin McDonald, among Williams' closest friends. They played alongside each other for Ponies and ran a law practice together, often dispensing their services to Ponsonby and Samoan players for free.
McDonald says: "He gave total loyalty, but expected it back. I remember my first game for Ponsonby in the early 1970s against a University team including Gary Weinberg, who was at Ponsonby the previous season.
"Gary had the temerity to swap to University ... Bryan and his brother Ken cut poor Weinberg to bits with early tackles, late tackles, high tackles."
Ponsonby were the city's glamour club, but didn't always get results to match the reputation. Williams, who started coaching in his mid 20s, was pivotal, with others such as Lin Colling, in moulding a winning unit and bringing the title to Ponies after a 22-year break.
Some of the stars didn't always make it easy. Opponents from those days still delight in recalling the onfield arguments between the giant test locks Andy Haden and Peter Whiting.
Williams says: "It's true all right - they were two big personalities and always wanted the lineout calls their way. There was always an edge to their relationship.
"One night we had this big barney up at the tan, about the same old things, with Maurice Trapp involved as well. I lost my cool and let them all have it.
"Andy and his wife Trish, and my wife Lesley and I, were living together and I was on cooking duties. I had to cook Andy's dinner that night. It was a very frosty atmosphere."
Williams recalls the working bees and other activities which not only funded Ponsonby's overseas trips in the 1970s and early 80s but built team bonds.
Others recall that while big-name players were not always on hand for the section clearing and housie nights etc, Williams never missed.
One trip led to the Harlequins forward Trapp joining Ponsonby, creating the history-making coaching partnership with Williams. Their Ponsonby high point was an unbeaten 1983 season, and they lost just three games in five seasons with Trapp as head coach of Auckland and Williams in his preferred position as assistant.
Two of those losses came when Auckland had several star players away with the All Blacks.
Back to Ponsonby. In his 1999 book on the club, sports statistician and historian Paul Neazor dared to wonder if Ponsonby "would be a thing of memory by now" but for Bryan Williams. During tough financial times in the 1990s, Williams shouldered the responsibility of club treasurer, and was in a core group who raised more than $200,000 to make the club debt-free.
McDonald says: "I know lots of rugby guys from all over the city, and there isn't anyone like Bryan Williams, a great All Black who has given so much to his club for so long.
"He would play for Ponsonby on painkillers and I remember at least one occasion when he played the day after a test. Other All Blacks would say they weren't quite right, that they had a test coming up, but never Bryan. It's not in his psyche. He's true-blue and incredibly loyal to friends."
"For a man who has been to such heights to do what he has done ... I think you're more likely to find characters like BeeGee in Canterbury or smaller places around the country, but not really in Auckland."
3 things about BeeGee
Ponies rule
Ponsonby won 10 of 11 Gallaher Shields under Williams' rugby directorship from 2001 to 2011.
Player and coach
As a coach, he was pivotal in turning Auckland rugby around in the 1980s as he and Maurice Trapp built on the foundations laid by John Hart.
38 tests for ABs
Williams played 131 matches for Auckland 113 matches for the All Blacks, including 38 tests.
