Marlborough Girls and Hornby High School have both won division six times since the girls competition started in 1984.
There are 52 teams and 520 players competing in the annual three-day tournament which started in Dunedin yesterday.
Bayfield was competitive in a closely fought first set won by Marlborough 25-19. Marlborough stepped up to another gear in the second set to win 25-6 and take the tie 2-0.
Riccarton won the girls division one title last year but is not expected to challenge Marlborough Girls and the other favourites, Aranui and Burnside, from Christchurch.
Waimea College, the winner of six titles, is favoured to retain the boys division one title in the annual boys competition that started in 1974.
Challenging Waimea College for the boys title this year will be Middleton Grange and John McGlashan College.
Kings High School, the dominant school in the first nine years, has won the tournament 11 times.
The tournament was last held in Dunedin six years ago and this year, 42 of the teams are from outside the city.
Eight of the nine courts in use are at the Edgar Centre or the Lion Foundation Arena, with a court at Bayfield High School also being used.
The tournament is watched closely by the New Zealand selectors and eight of the 11 members of the New Zealand under-20 team that played in the Asia Challenge in Thailand in October have played in the event.
Two former members of the elite New Zealand team, Tom Casey and Craig Seuseu, were members of the St Paul's High School, Dunedin, team that won the tournament in 1986 and 1988.
The finals will be played at the Lion Arena tomorrow afternoon, with the girls final starting at 2.30pm and the boys final at 4pm.
