Just one point separates the top two, so it will be winner-takes-all at Blagdon.
In the unlikely event of a draw, then the title will go to Saltash.
Ashes will go into the game in good heart after trouncing Bude 68-17 last week. That match saw Max Venables score a staggering 38 points.
Venables could come up against his former Plymouth Albion team-mate Mark Lee on Saturday.
Another former Albion old boy, Wayne Reed, is also still on the books of Crediton.
Both sides have only lost once all season and are guaranteed promotion to Western Counties West, but both want to go up as champions.
When they teams met at the start of the campaign, Crediton narrowly won 27-24 at Moorlands Lane.
Elsewhere in the Cornwall/Devon League, already relegated OPMs travel to Hayle, and bottom side Liskeard-Looe visit Honiton.
Ivybridge will be able to experiment when they travel to 10th-placed Clevedon on Saturday in South West One West.
The Cross-in-Hand side have already secured runners-up spot and now have time to prepare for their promotion play-off match against the second-placed side from South West One East.
Devonport Services will secure a top six finish in Western Counties West if they beat bottom side St Ives at The Rectory on Saturday.
Meanwhile, Tavistock will end their stay in that division with a home match against leaders Teignmouth.
There is a big game in Devon One where second-placed Plymstock Albion Oaks entertain third-placed St Columba & Torpoint.
Oaks are five points clear of their rivals and so will claim runners-up spot and a place in the end of season play-offs if they pick up a point or deny Saints a full five points.
Champions Plymouth Argaum end their league season away at Topsham, while Old Techs entertain Torrington.
In Devon Two, Tamar Saracens still have hopes of claiming the title. They go into the final weekend two points behind leaders North Tawton.
Sarries travel to third-placed Salcombe, while North Tawton are away at fourth-placed Dartmouth.
Elsewhere, DHSOB entertain Ilfracombe and Plympton Victoria travel to Buckfastleigh.
South West One West: Clevedon v Ivybridge
Western Counties West: Devonport Services v St Ives, Tavistock v Teignmouth
Cornwall/Devon: Crediton v Saltash, Hayle v OPMs, Honiton v Liskeard-Looe
Devon One: Plymstock Albion Oaks v St Columba & Torpoint, Topsham v Plymouth Argaum, Old Techs v Torrington.
Devon Two: Buckfastleigh v Plympton Victoria, DHSOB v Ilfracombe, Salcombe v Tamar Saracens.