OBM took the result 48-36 after a sublime effort on attack in the opening stanza.
Robbie Rollo and Renata Tenana each scored a brace as the backline were well marshalled by Northland first five Peter Breen.
They took a 36-12 lead into the break, giving Kamo a tall task to get back into the contest.
But they did just that as they maintained possession through the second half, getting across the line three times to close the scores.
The backline did their part as Matt Burns, Kalib MacDonald and Kurt Davies all crossed for tries. Loose forwards Blake Haora and Jordan Otene also dotted down, while first five Tom Herman was again accurate off the kicking tee.
While OBM secured the win, they suffered serious injuries which will see them depleted over the next three or four weeks. Kamo again showed they are a team capable of pushing any team and will be a real threat to the top four.
OBM coach Greg Shipton was happy with the effort from both his side and the reserves.
"To win both games away against Kamo is always special. However, while Kamo showed great improvement, we as a team need to be better if we want to progress from the looming semifinals," he said.
Meanwhile the Western Sharks helped their playoff cause with a tense 26-22 win over bottom-placed Mid Western.
Mid Western have shown promise in the past two weeks but Sharks proved too good in the late stages to pick up a much needed win.
Hora Hora made the most of a high scoring contest against Otamatea where over 100 points were scored in fantastic conditions.
Hora Hora took the match out 65-36, keeping them right in the playoff hunt.
Mid Northern found the going tough against a spirited Wellsford side but grabbed the 24-23 result - their second straight tight win.
The final match saw Waipu comfortably account for Hikurangi 48-5, adding another twist to the finals race.
Results: Premier
OBM 48 Kamo 36
Western Sharks 26 Mid Western 22
Horahora 65 Otamatea 36
Waipu 48 Hikurangi 5
Mid Northern 24 Wellsford 23
Reserves
OBM 19 Kamo 13
Western Sharks 37 Mid Western 12
Otamatea 41 Horahora 36
Waipu 58 Hikurangi 0
Mid Northern 65 Wellsford 5
Championship Finals
Kerikeri 46 Moerewa/UK 28
Tomarata 22 Ohaeawai/Okaihau 12
Awanui 69 Whangaruru 25
Kaihu won by default
Eastern 26 Kaitaia 26
Kaeo 62 Otiria 12