The Tauranga fighter said he was looking forward to taking on his opponent at the Rotorua Girls' High School Arena in December.
"Spence was my boss for five or six years. I've worked in four or five different jobs and Spence has given me a job every time and I have a lot of respect for him."
Wong Sang who has lost 12kg for the fight jokingly said he was ready to defend the trophy for Bridges - who currently keeps the trophy in his office in Tauranga.
"I think Spence has got as much chance of winning as Phil Goff has of winning this year's election - of course I'm nervous but I'm quietly confident," he said.
Spence 40, was equally quick with his witty reply saying he would be showing the 37-year-old who was the boss inside the ring as well.
"I don't mind a bit of hard work especially for a good cause. It's like rugby, it takes a full 80 minutes so we will see how he is at the end of the third round."
The father of two took up the challenge of boxing because he was inspired by his wife Emma McClintock who fought in last year's corporate fight night.
It is the third year the fights have been held and the pair's fight is one of 12 corporate fights planned for the night.
The event is organised by Rotovegas Boxing Gym and the money raised from is used to buy training equipment for the young fighters who train at the club.
Tickets for the event are now on sale at Go 360 Gym on Eruera St and Golds Gym on Old Taupo Rd.
Ringside corporate tables which seat 10 will cost $2000 and fight-night experience tables are also on offer at $1500. Both tables include food and beverage.
For more information on booking tables or general admission tickets contact Tanya Warren on 07 345 3085 or 027 548 2692.