It gained a bonus point for four tries and will next play fifth-placed Whanganui which is two points behind.
East Coast’s ability to drag North Otago down to its level meant the game was a muddly one until North Otago became more decisive in its attack in the second half.
"It was all about patience" coach Nigel Walsh said.
"Once again the boys got out there and tried to score for the first phase but eventually we got around to building up a series of phases and the gaps and the tries came."
North Otago scored in the first two minutes of the game when from a tap penalty from 40m out winger Matthew Vocea romped over for a try which fullback Josh Buchan converted from wide out.
Fourteen minutes later, Antini Brown and Lemi Masoe combined to set up a ruck from which No8 Filipo Veamatahau burst clear to send fullback Josh Buchan in for a try which he converted.
East Coast came back when first five-eighth Verdon Bartlett chipped ahead and left winger Epeti Lotawa outpaced the defence to score between the posts for fullback Kris Palmer to convert.
Josh Clark, who dominated the lineouts, and flanker Morgan Dawes combined 15 minutes from halftime and Veamatahau was the link man to send winger Conner Newlands in for a try which Buchan converted. Clark went high to grab possession five minutes later from a kick ahead and Brown kicked deep into East Coast territory where flanker Dawes grabbed possession and props Ralph Darling and Meli Kolinisau combined to see Buchan hand on to centre Lio Lolo to score for Buchan to convert.
Two minutes from halftime, second five-eighth Masoe broke 30m down field from broken play and halfback Robbie Smith sent Newlands across for his second try which Buchan converted to give North Otago a 35-7 halftime lead.
"At the end of the day we knew that we had to score at least five tries and we wanted to give a good performance to give us some confidence for the next week against Whanganui but I wasn’t happy with the start as we began playing East Coast’s game," Walsh said.
"We got loose and tried to be flairy instead of attacking directly. We had to be more disciplined and more patient and the gaps began to come after three or four movements."
North Otago lock Jared Whitburn had probably his best game in the gold jersey and at times his efforts were inspirational.
Seven minutes into the second half, Whitburn was rewarded with a try to take North Otago out to 40-7 but East Coast came back midway through the half with a try to centre Peehi Fairlie for Palmer to convert.
Whitburn burst from a ruck three minutes later and first five-eighth Dan Lewis, who had replaced Antini Brown, sent Vocea in for his second try which Buchan converted.
In the final five minutes, North Otago ran in tries to replacement half Inoke Naufahu and, Veamatahau broke from a scrum for Lewis to touch down.
- Terry O'Neill