Anderson celebrated his call up to the Black Caps with the innings of the match, as he smashed the bowling all over the picturesque Bay Oval, hitting 12 fours and five sixes in his maiden century for the Bay.
He was finally out for 109 when he was caught off the bowling of former Bay left arm spinner Mitch Sweetman.
Anderson is still coming to terms with his unexpected selection in the Black Caps team for the Twenty20 and ODI part of the South African tour.
"It is one of those things when you are growing up as a kid you dream of playing for New Zealand, and your aspirations are always to do well and play for them," said Anderson.
"So for me to get that call on Thursday morning, which was pretty much out of the blue to be fair, was unreal. I spoke to my family straight after and they were ecstatic about it.
"It hasn't really sunk in yet but hopefully when I jump on the plane and head over there it will.
"The shorter forms of the game are the easier way to introduce guys into the international scene," he said.
"But the pinnacle is still to play test matches for your country and that is probably on the top of the list."
Anderson has loved playing cricket in the Bay since he moved to Tauranga from Christchurch before the season began.
"It meant a lot to score my first hundred for the Bay. They put a lot of emphasis on doing well and taking pride in it so I have loved every opportunity to play for them, and for Cadets even though I have only had one game.
"There is a good culture in the Bay team so I love it."
After the new Black Cap's swashbuckling innings was over, the Bay tail wagged and the last pair of Aldridge (17) and Boult (18 no) took their team through to 333.
Boult and Aldridge took a wicket each late in the day as Counties Manukau reached 40/2 at stumps.
The early battle on day two belonged to the Bay bowlers and at 189/8 Counties declared their first innings in order to try for an outright win.
The Bay of Plenty batsmen had a quick thrash against some below-standard B Grade bowling, scoring 117-3 off just nine overs, to set Counties Manukau 259 off 55 overs to win the match.
They certainly started well, with a fine opening partnership of 94 from Ash Vodnala (47) and Jonny Bassett-Graham (43), before Williamson wove some magic with his right-arm offspin bowling. Williamson took 5-36 to rip the heart out of the Counties Manukau innings, with Aldridge and Jono Boult grabbing two wickets apiece, as they were bowled out for 178.
Fergus Hickey Rosebowl: Bay of Plenty 330 (Corey Anderson 109; Peter Drysdale 78; Bharat Popli 38, Kane Williamson 35; B Arnel 3/41; A Vodnala 2/42, I Sodhi 2/72) & 117/3 declared (Brett Hampton 26, Jono Boult 26) Counties Manukau 189/8 declared (N Kelly 35, D Jones 35; Graeme Aldridge 3/24, Tony Goodin 2/22, Trent Boult 2/27) & 178 (A Vodnala 47, J Bassett-Graham 43; K Williamson 5/36, G Aldridge 2/22, J Boult 2/56). Bay of Plenty won by outright victory.