Wayne Aziz opened the scoring for Edgehill with a header from a corner after only 10 minutes, then Seamer keeper Jordan Wood made several superb saves to keep the hosts in the game.
The hosts gradually gained a foothold in the game and levelled when Danny Glendinning pounced to slot in the equaliser five minutes before the interval.
Seamer continued to take the game to Edgehill after the break, then Tyson Stubbings produced another good save from Wood but the rebound fell to Jackson Jowett, who found the back of the net.
Five minutes later Stubbings again produced a sublime bit of skill, running at the heart of the Seamer defence to end in a penalty being awarded, and sub Liam Salt smashed home the spot-kick.
Wood pulled off more top saves to keep the score down, but he could do nothing about a superb Jowett chipped shot after he raced around several Seamer defenders.
Edgehill boss Steve Clegg said: "There were a lot of good performances for the team in which Stubbings was picked as man of the match This gave us a very important victory for the squad over a strong Seamer team."
Gary Lawton put in a commanding performance in midfield for Seamer, who were hampered by the absence of an injured Tommy Adams (back) and Kris Tate limping off after only 10 minutes due to a hamstring injury.
Wood also put in a cracking display to keep the score down for the hosts.
Defending champs West Pier kept their title hopes alive with a 3-1 win at Newlands.
The home side opened the scoring when a well-worked move was finished off by Mike Wilson, but Pier levelled when Jonny Manson fouled Jamie Bradshaw in the area and Martin Cooper slotted in the penalty.
In a very tight first half there were no further goals but five minutes into the second half Bradshaw's tidy finish put Pier in front.
Newlands pushed hard for a leveller but Pier always looked lively on the counter-attack and after squandering a couple of chances to seal it, Tommy Barker added a third for the away team in the 82nd minute.
Bradshaw was named as Pier man of the match for an excellent show up front, while Ady Blake and Niall Gibb also impressed in defence.
Filey Town worked hard for a 3-0 win in a scrappy game at struggling Flamborough.
Stu Dickens put the visitors in front in the first half, but Boro almost levelled from the spot, but their effort was saved by Kyle Scaife.
Town pulled clear in the second half thanks to a goal from Ricky Tomlinson, then more fine team play from the visitors was finished off by Dean Carr for the third goal.
Town player-manager Jordan Philliskirk said: "It was not a great playing surface and it made it very difficult to play any free-flowing football on.
"We worked hard and in the second half we were always in control but we were thankful for Kyle's save in the first half from the penalty.
"It was such a good team effort that all the lads deserve a share of the man of the match award."
Hunmanby United edged away from the wrong end of the table with a 3-0 win at second-from-bottom Goal Sports.
Leigh Franks' side went in front in the first half with a tap-in from Olly Milner, but the home side also played their part in a very even opening 45 minutes.
United were the better team after the interval, and 20 minutes into the second half James Pinder scored after fine approach play from midfielder Daz Crawford.
Ben Briggs headed in the third goal from a Crawford corner to seal the win.
Franks singled out Andy Wardell as the man of the match for United for a strong show at right-back, while Crawford also played superbly, while sub Robbie Harrison came off the bench and again had a big impact on the game and almost netted a goal.
Goal Sports keeper Marc Wain and striker Gav Wood shone for the home side.