The rain did not let up for the final showdown between the top two teams, Rangataua and Melville, with Melville coming up with a 54-3 win.
Rangataua were the first to get points on the board with an early penalty from Zoe Wilson in the opening minutes.
But for the home team, who were missing a number of Black Ferns players, those three points would be the only ones scored.
Waikato's Melville showed dominance from the beginning, despite not having a coach on the sideline, with four tries scored in the sixth, ninth, 12th and 32nd minutes.
No conversions were successful and at halftime the score sat at 20-3 to the visitors.
The floodgates opened in the second half for Melville with six more tries placed over the line and one successful conversion.
Rangataua coach Paul Pou said despite the loss the day was "fantastic" for women's rugby.
"It's a great spectacle for women's rugby and a good example of what can happen when everyone comes together," he said.
Rangataua played off the back of a close defeat of Rangiuru in the Baywide Premier Women's final last week.
Pou said to end the season with the loss to Melville was "sad" but the final against Rangiuru was the team's main focus in recent weeks.
"Our whole season has been one of the best coaching years I've had in my life," he said.
Melville manager Kurdis Skudder said she was proud of her team for travelling to the Bay not knowing what to expect and without a coach.
Skudder said she had been texting coach Honey Hireme throughout the game, who was "so happy" to hear her team took the win.
Skudder said the Battle of the Kaimais was a good opportunity to combine the women's team to see how the sides compare.
"I thought they [Rangataua] were awesome, it was good to just see how they're doing and to go up against the best in the Bay," she said.
"The conditions were a bit slippery, a bit wet and cold but I think everyone did awesome."
Battle of the Kaimais
Whakarewarewa 49 Southern United 5
Waikite 0 University 86
Rangiuru 12 Hamilton Old Boys 29
Rangataua 3 Melville 54
