Devon One leaders Argaum sit eight points clear of second-placed Oaks with just two matches to play.
A win or a draw on their home soil will secure Argaum, last season Devon Two champions, the league title and promotion to the Cornwall/Devon Division.
However, they could still be crowned winners even if they lose, providing they pick up a bonus point and Oaks fail to score four tries. If Oaks are unable to spoil Argaum’s party then their hopes of claiming second and a place in the play-offs could be under threat from St Columba & Torpoint.
The Saints, who entertain second-from-bottom Old Techs on Saturday, sit third, five points behind Oaks, who they meet on the final day of the season.
Elsewhere, Ivybridge will be hoping to guarantee themselves second spot in South West One and a place in the play-offs for promotion to National Three South West.
Ivybridge, who are 10 points clear of third-placed Bridgwater with three games to go, travel to fourth-placed North Petherton.
Tavistock, however, could be relegated from Western Counties West this weekend if they lose at home to Penryn.
In the same division, seventh-placed Services will be looking to close the gap on fifth-placed Truro when the sides meet at the Rectory.
Saltash secured promotion to Western Counties West last weekend, but they still have their eyes on the title. They and Crediton both sit on the same points with three matches to go.
Ashes, who lie top with a points difference of more than 200 better than Crediton, travel to eight-placed Bodmin, while their title rivals entertain Paignton.
At the other end of the table, OPMs need a win against the team just above the, Exeter Saracens, to have any hope of avoiding relegation. Exeter will start the weekend seven points above OPMs, who are third from bottom.
In Devon Two, Tamar Saracens will be keen to keep their title hopes alive when they travel to neighbours DHSOB.
Sarries are two points behind leaders North Tawton with two games to go.
Bottom side Plympton Victoria entertain third-placed Salcombe.
South West One: North Petherton v Ivybridge
Western Counties West: Devonport Services v Truro, Tavistock v Penryn
Cornwall/Devon League: Bodmin v Saltash, Exeter Saracens v OPMs
Devon One: Plymouth Argaum v Plymstock Albion Oaks, St Columba & Torpoint v Old Techs.
Devon Two: DHSOB v Tamar Saracens, Plympton Victoria v Salcombe.