"Two years ago they were bottom of the competition so I'm very proud of the season so far," Nitz said.
"Our senior players have stepped up to the mark this year. Our younger players are keen to learn from them.
"It has been enjoyable seeing them progress over the last two years," he said.
He is preparing his side for an intense forward battle.
"Last time we met, they beat us through the forwards. We've probably got the best backs in the competition. Our plan is to use our backs."
Opotiki coach Richard "Digger" Wilson agrees.
"The girls are really amped about this game ... our forwards are pretty tough to compete against. We've probably got the best forward pack, country wide, at the moment. But the Te Puke backs are pretty lethal."
The winners will advance to represent Bay of Plenty in the national girls' knock-out competition, and will host the winners of the playoff between the Waikato and Counties qualifiers on August 30.
Girls' 1st XV Finals Day
Blake Park, Mt Maunganui, today
9th/10th: Tauranga Girls' College v Rotorua Lakes High School, 1pm
7th/8th: Whakatane High School v Te Wharekura O Mauao, 2.15pm
5th/6th: Rotorua Girls' High School v Trident High School, 1pm
3rd/4th: Taupo Nui-a-Tia College v Western Heights High School, 2.15pm
Final: Opotiki College v Te Puke High School 1, 3.30pm.