Seamer sealed a tense three-run victory against Staxton to go top of Division A with just one game remaining.
Gregg Chadwick’s 49 helped Seamer post 131-6 before Staxton fell agonisingly short on 128-3, Dave Morris having hit 44 and Chris Dove 27 not out.
Seamer’s win moved them top of the pile and two points clear of both their opponents Staxton and Heslerton, who beat Cayton to condemn their visitors to relegation to Division B.
Tom Ward hammered an unbeaten 61 in Cayton’s 141-3, but it wasn’t enough as wily all-rounder Andy Slaughter hit 80 not out a Heslerton cruised to 145-2 and the victory in reply, keeping their title hopes alive and confirming Cayton’s relegation.
Ganton kept their hopes of avoiding relegation alive with a 10-run win over Ebberston.
James Pick’s 40 helped Ganton make 129-8, Frankie Beal taking 3-24.
Liam Cousins then bagged three wickets for 14 runs to restrict Ebberston to 119-7 despite Ben Lockey’s 40 and 34 from Cooper Barnes.
Champions Filey grabbed a hugely-important win in their bid to avoid the drop, beating Folkton & Flixton by six wickets to end their opponents’ title aspirations.
Once again Aussie Tom Fitzgerald fired Filey to victory, taking 3-17 to ensure Flixton were all out for 67 before scoring 35 to help his side to 72-4.
Seamer will wrap up the title with victory at Ebberston next Tuesday, although Staxton and Heslerton will be hoping the leaders slip up and they can win at Cayton and Ebberston respectively to end up in top spot.
Ganton need to beat Filey to stand a chance of staying in the top-flight and remarkably condemning the champions to relegation.
Wykeham wrapped up the Division B title thanks to a crushing 68-run win at Sherburn.
Jack Holt hit 88 and Joe Bradshaw 75 in Wykeham’s 194-2, Holt then taking 3-19 as Sherburn made their way to 126-9.
Cloughton look set to join Wykeham in the top-flight, but they suffered a one-run loss at Scalby.
Jon Barton’s unbeaten 47 and 30 from skipper Bradley Walker helped Scalby to 118-3 and despite Cloughton captain Liam Salt making 62 not out in their reply, the visitors fell agonisingly short as Ed Hopper took 3-17.
Folkton & Flixton B remain in third spot after they beat Forge Valley by 83 runs, resulting in their relegation to Division C.
Will Hutchinson (56), Freddie Gunning (51no) and Finlay Ward (40) were among the runs in Flixton’s 183-5 before Alex Potter bagged 3-35 as Valley collapsed to 100 all out, John Flinton hitting 40.
Cayton B’s relegation was also confirmed as they fell to an 88-run defeat at home to Scarborough.
Glyn Botterill was the star man for Scarborough with bat and ball, making 64 in Scarborough’s 152-7 before taking 4-9 as Cayton were all out for just 64.
Cayton B and Forge Valley will be replaced in Division B by Brompton and Seamer B after the pair wrapped up their respective promotions from Division C.
Brompton wrapped up promotion with a comfortable nine-wicket victory over Snainton.
Snainton finished up on 86-6, which Brompton chased down with ease, Tom Fletcher-Varey making 37 not out and Tom Noble 26 not out.
Young spinner Archie Graham impressed as Seamer B beat Ebberston B to confirm their promotion and ensure the battle for the title goes down to the wire.
Dave Graham (68), T Greenwood (35) and Matthew Sheader (25) helped Seamer to 171-5 before young leg-spinner Archie Graham took 5-28 as Ebberston finished up on 147-9, Neil Eddon hitting 54 of those.
Scalby B moved off the foot of the table courtesy of a two-run win at Muston.
Scalby’s 99-6 proved sufficient by a small margin as Muston finished up on 97-8, Matthew Atkinson making 53 of those as veteran Adrian Hollingsworth took 3-12.
Ravenscar cruised to a seven-wicket win at Wykeham B, the hosts all out for just 56 before Shaun Bayes’ 28 helped the visitors to 59-3.
Forge Valley B are now bottom of the table after they failed to raise a side for their game at Staxton B.