Seamer were left devastated as table-toppers West Pier left will all three points after a last-gasp winner.
Pier started brightly and led after Neil Thomas converted Sam Garnett’s pin-point cross, but after that it was all Seamer.
The hosts levelled after 35 minutes when sub Lewis Tiffany nodded in superbly.
Paddy Parke’s men were the brighter side after the interval and would have gone ahead if it wasn’t for some superb goalkeeping from Pier stopper Kyle Scaife.
And the away side nicked the points with just two minutes left on the clock when Gary Thomas scrambled home.
Pier boss Spivey said: “Seamer can feel very hard done to to not even get a point when it looked like they could have got all three.”
Parke added: “I’m gutted for the lads because they put everything into the game and deserved something out of it.”
Pier’s title rivals all recorded comfortable wins and boosted their goal difference in the process.
Edgehill beat Westover Wasps 8-2.
Edgehill led 3-1 at the interval and never looked back, taking their lead to 8-2 before a late consolation.
Ricky Greening, Liam Cooper and Danny Collins all grabbed braces while Phil Warnett and Kurtis Henderson wrapped up the scoring, man of the match Henderson grabbing the goal of the game after cutting in and smashing a left-footed effort in off the bar.
Josh Young scored both of Westover’s goals.
Newlands smashed eight past United Sports Bar as they strolled to three points.
Sean Exley was in form in front of goal as he smashed in five, while Adam Stride fired in a hat-trick for Shaun Mancrief’s men.
Mancrief singled out Exley, Michael Wilson and Jonny Manson.
Filey Town cruised to a 10-0 success at home to relegation-threatened Sleights.
Two first-half headers from Danny Price and an own goal gave them a 3-0 lead at the break, before they smashed seven in during the second 45 minutes.
Boss Jay Taylor introduced Cameron Dobson at the interval and the front man smashed in a hat-trick, while Ricky Tomlinson grabbed a brace and there were goals for Tommy Wilson and Phil Dickens.
Taylor said: “It was a very good team performance that keeps us in the mix.
“We’ve got to play West Pier twice so they will no doubt be important games for us.”
Taylor picked out Wilson as his side’s star man.
Hunmanby United and Ayton remain in the bottom two after they both suffered defeats.
Hunmanby suffered a 7-3 defeat on the road at Whitby Fisherman’s Society.
Neil Hart was the Fisherman’s star man as the striker came off the bench at half-time to smash in a hat-trick and help Mark Storr’s men on their way to a crucial win.
Sam Bailey also grabbed a hat-trick and the impressive Danny Winspear headed in Fisherman’s other goal.
Rock-bottom Ayton suffered another defeat against Ryedale.
Neither side could find the net during an uneventful first 45 minutes, but Ryedale led when Martin Foxton smashed in after good work from Dan Greaves.
The away side made sure of the three points when Harry Reed fed Jordan Thackeray, who left his marker for dead before crossing for Martin Myers to fire in for 2-0.
Tom Tate was man of the match for the victors.