Former Counties Manukau representative Vaughan Blanchard also came to the Rotorua party with a hard fought 80.
Western Bay bowler Josh Dwight backed up from his five-wicket bag the previous day to grab three wickets for 39 runs.
As the Western Bay team openers walked out to start their innings, few would have imagined the drama to come.
The Rotorua bowlers held the early momentum, including a miraculous catch from Alistair Blackett, to have the combined Mount Maunganui and Te Puke club representatives in some trouble.
At one stage the run rate ballooned out to nine runs an over, before Ben Musgrave (62) and Blair Parlane (55) fought back.
A ninth-wicket partnership between Matt Golding (31no) and Josh Dwight tied the score, with one ball remaining in the match.
Despite a voracious appeal by the Rotorua side for lbw, the umpire called a leg bye and the game finished with Western Bay grabbing a one-run victory.
Meanwhile, Tauranga rebounded from their loss to Western Bay on Saturday, to grab the win points in the other match-up at Fergusson Park against Eastern Bay of Plenty.
Attrill Cup results from Sunday:
Rotorua 233/4 (Jason Trembath 111, Vaughan Blanchard 80; Josh Dwight 3/39) lost to Western Bay of Plenty 234/8 (Ben Musgrave 62, Blair Parlane 55, Matt Golding 31no, Mitch McCann 21; Andrew Gibbs 3/32, Alastair Blackett 3/77)
Eastern Bay of Plenty 178 (Joe Barrett 44, Devon Bell 29; Sean Dykes 4/17, JJ Boult 2/26, Gurinder Singh 2/42) lost to Tauranga 179/8 (Tommy Clout 41no, Kent Hodder 41, JJ Boult 32, Cameron Neal 25; Owen Smithson 4/40)
Attrill Cup final points:
Western Bay of Plenty (Mount Maunganui/Te Puke) 9, Rotorua 4, Tauranga 4, Eastern Bay of Plenty 0.