Northland currently leads Rewa at half-time by 13-7 in the final of the Vodafone Vanua Championship at Lawaqa Park.
Northland scored a try from lock Peniasi Wakawaka with fullback Saint George Talei adding a conversion and a penalty.
Northland pivot Emosi Mulevoro also added a drop goal.
Rewa outside centre Taito Rauluni scored the sides lone try with fullback Apenisa Deve adding the conversion.