Cotter showed her finesse once again in the second quarter, scoring her 17th goal of the season, smashing the ball into the net to go 2-0 up.
Havelock managed to get on the scoreboard in the second quarter with a goal from Annette Watson, set up by lovely play on the left wing by Jess Tucker.
Napier scored the only goal in the third with a lethal shot by Amy Rowlands to pull ahead.
Havelock pulled one back in the fourth, but their efforts weren't enough to overcome Tech after Sarah Wilkinson sealed Tech's deserved victory by tapping in a penalty corner in the final minute of the match.
Napier coach Holly Varcoe said there was no way her side were going to lose.
"The Hawke's Bay Today headlines were enough ammunition for us to win, when we saw that people were encouraged to come to the finals wearing pink - well that just did it," Varcoe said.
A block of red could be seen in the grandstand in support of Tech, outweighing the supporters in pink.
Varcoe said Havelock had become a good team but were outclassed by her girls.
"Our attack was relentless. We had an internal competition with Hannah, Amy and Sarah sitting on 15 goals each before the final," she said.
"They were out to beat each other and all got on the scoreboard. But young Cotter edged them out with an extra goal."
Havelock co-coach and former Black Stick Emily Gaddum said she was pleased with the fight her team showed despite the loss.
"They were just a little bit too strong for us and produced some really slick goals," Gaddum said.
"Each year we try to come back and beat Tech. It's a close competition now between the top four - we'll go again next year."
Hawke's Bay Hockey representative Michelle Francis said finals day and the hockey season as a whole has been a success despite the challenges.
"The competition may have been shortened but it allowed all clubs the opportunity to have a meaningful season. Finals day was balmy but the intensity and level of hockey was outstanding," Francis said.