Sir Brian told the crowd he had no idea the stand was going to be named after him.
" ... Until I got the Times-Age. I said, what the hell is this?"
He said it was an "amazing shock" but an honour as well.
"I just hope, if someone surpasses what I have achieved, they change the name of the stand."
He acknowledged Bob Francis and Wairarapa Bush chief executive Tony Hargood as "two major drivers" in the refurbishment of the grounds.
"It's a wonderful opportunity to lead New Zealand in a lot of ways."
The turf meant youngsters could play their game all year, in the same conditions, "any time, day or night".
For the youth who left sport because they wanted their weekends, he said: "There's no bloody excuse now, kids - you can play any night of the week."
Students from Masterton Intermediate, Carterton School and Chanel College performed a haka, their uniform colours representing Wairarapa Bush rugby.
The Chiefs won, 37-15.