Edgehill's title charge suffered a blow as they lost 5-4 against Seamer at the Flamingo Land Stadium tonight.
League top-scorer Danny Glendinning grabbed four goals for Seamer, with Danny Price netting the other goal for Matty Dawson and Tommy Adams' side.
Luke Jones and Kieran Link both bagged a double apiece for Steve Clegg's Edgehill side.
Four-goal hero Glendinning and Price were Seamer's standout performers.
Seamer now lie just one point below the league leaders, while Pier are 10 points adrift but have four games in hand.
Newlands battled to a 2-0 win against Filey Town in a game switched to Oliver's Mount.
Adam Stride and Stew Bates scored the goals for Joe Hakings' side, Gary Jordan was their man of the match.
James Jenkinson donned the gloves for Town and impressed between the sticks.
Flamborough failed to raise a side for their game at West Pier.
In Division Two, two Callum Myers goals sealed a hard-fought 2-0 win for league leaders Itis Itis Rovers against Commercial.
Ellis Wilson was star man for Rovers, while right-back Macauley Riley was Commercial's man of the match.
A superb solo effort from Tyler Beck helped Ayton to a 1-0 win against Sherburn.
Joe Bradshaw and 17-year-old Dan Tomlinson shone for Ayton while Liam Scott and Harry Ward impressed for Sherburn.
Edgehill 3rds beat Ayton Reserves 7-4 in the Reserve League.
Matthew Burling hit three of Edgehill's goals, their others coming courtesy of a Kyle O'Toole double and strikes from Lee Cappleman and Martin Jenkinson.
Player-boss Steven Frederiksen hit a super long-range effort, with their other goals coming via a Si Coupland hat-trick.
Adam Cattle was their man of the match.
West Pier Reserves beat Scalby Reserves 4-2.
Rich Tolliday bagged a screamer and Mike Anderson, Zac Hansen and Kurt Williamson scored Pier's other goals before the Otters hit consolation goals via Sam Foy and Jack South.
Filey Town Reserves beat Newlands Reserves 4-1.
Joe Gage hit a brace, Max Gage hit one and Ryan Baldry, a recent signing from fierce rivals Hunmanby United, notched their other goal.