After back to back draws, the unbeaten St Pauls had started Wednesdays round level on four points with Mount Albert Grammar School and Otahuhu College but the landscape has now changed significantly.
Playing at Otahuhu College, St Pauls had an 18-4 victory to move to six points while Mount Albert Grammar lost out 8-10 in a tight tussle with Kelston Boys High School.
In the remaining match Westlake Boys High School beat Sir Edmund Hillary Collegiate 10-6.
With one round left next week to find the semi-finalists, St Pauls College is on six points, Kelston and Westlake are both on five, Mount Albert and Otahuhu on four and Sir Edmund Hillary on 0.
In next Wednesdays final matches, Mount Albert Grammar is home to St Pauls, Westlake hosts Kelston and Sir Edmund Hillary is at home to Otahuhu.
Results of fourth-round matches:
Sir Hillary Edmund Collegiate 6 (Pousini Ionga try; Paula Sopilano goal).
Westlake Boys High School 10 (Willy Leaae Toa, James Waterson tries; Ben McIntyre goal).
Mount Albert Grammar School 8 (Nathaniel Roache, Sam Lulia tries).
Kelston Boys High School 10 (Joeveni Leota, Joe Ngaham tries; Zion Ioka goal).
Halftime: 40 Mount Albert Grammar.
Otahuhu College 4 (Don Seuala try).
St Pauls College 18 (Taniela Leka, Paul Nuia, Bradley Abbey tries; Bradley Abbey 3 goals).
Halftime: 412 St Pauls.
Southern Cross Campus 40 (Okomaka Talagi 4, Birdsall Faapepele, Brandon Togiamua, Lisiate Vaihu, Viliami Maamaloa tries; Lisiate Vaihu 3 goals; Filigatauivi Tafa goal).
Henderson High School 8 (Mose Esera, Shane Fuataga tries).
Halftime: 148 Southern Cross.
Papatoetoe High School 18 (Kelepi Holi, Braxton Edmonds, Ises Aiga tries; Braxton Edmonds 3 goals).
Avondale College 16 (Tom Leota, Don Tofae, Eucharis Savelio tries; Perry Kau 2 goals).
Halftime: 64 Papatoetoe.
Papakura High School 18 (Lucky Faisauvale, Sengli Malu, Arthur Crichton tries; Arthur Crichton 3).
Tangaroa College 6 (Josh Hefa try; Jalen Jackson gtoal).
Manurewa High School 44 (Erin Clarke 3, Ryan Asalele 2, Manuel Kiliva, Reuben Peauafi, Evander Siafa, Stewart Tafiti tries; Ryan Asalele 3 goals; Erin Clarke goal).
Rutherford College 0.
Halftime: 180 Manurewa.
Mount Roskill Grammar School 6 (Filipo Muavae try; Luke Edmonds goal).
Western Springs College 16 (Shechinah Tumu-Makara 2, James Dennis tries; Stacey McIntyre 2 goals).
Halftime: 64 Mt Roskill.
James Cook High School 6 (Tim Nove try; Harry Robertson goal).
Aorere College 4 (Joshua Alofipo try)
Halftime: 04 Aorere.