A 5-1 home win for Newtonmore over Fort William means 'More will lift a fourth consecutive Premiership title with a win at Kinlochshiel on 7 September.
Glen MacKintosh and Danny MacRae had Newtonmore 2-0 up within 26 minutes before Gordy MacKinnon pulled one back for Fort just before half time.
David Fraser, Michael Russell, and MacRae again, took the tally to five for the defending champions in the second half.
This result also deepens Fort William's relegation woes as the composition of next season's revamped leagues steadily takes shape.
But for Oban Camanachd, a second relegation from the Premiership in three seasons has already become a reality following their goalless draw with Kyles at Mossfield Park.
After taking the drop in 2011 they won South Division One to go back up last season but now, with two to go down, the only team they can catch is Fort William.
Inveraray went back third with a 3-2 success over Kingussie at The Winterton.
Lewis MacNicol opened for Inveraray but by half time Chris Hollysong and 48-year-old Kevin Thain had the score at 2-1 to Kingussie. However Gary MacPherson and Euan MacMurdo sent the game the way of the home side.
The third and final place in next season's National Division One for teams from North Division One has gone to Caberfeidh following a 1-0 victory in their final game against Strathglass in Strathpeffer.
A point was all Cabers needed, but they got both when Brian MacDonald grabbed the goal with 13 minutes left. This means that Skye, who led opposition to changes in the league structure, lose out.
Oban Camanachd's relegation also secured the corresponding place from South One for Glenorchy. Their only possible challengers, Camanachd's reserves Lochside Rovers, now become ineligible since no club can have two teams in the same division.
And barring an avalanche against them, Glasgow Mid Argyll should take the South Division One title against Bute in Rothesay on 7 September after victories for both this afternoon.
Mid Argyll beat Aberdour 4-0 while Bute overwhelmed Oban Celtic 12-1. Robert Walker got six, bringing his two game total to 13 and his team's to 24.
The north and south area reserve titles were also decided this afternoon when Lovat beat Kinlochshiel 5-2 for the Strathdearn Cup up north, and Ballachulish added the Bullough Cup to the Sutherland Cup when they defeated Kyles 3-0.