Edgehill beat Seamer 5-3 in their quarter-final clash.
Steve Clegg's side took the lead 11 minutes in, Jackson Jowett lashing across Seamer keeper Jordan Wood.
Parity was soon restored however, Ali Caw ghosting in at the back post to head in Joe Tiffany's racking diagonal ball.
Luke Jones then netted for Edgehill to restore their advantage, but back roared Seamer again, former Edgehill man Ricky Greening with their equaliser.
Edgehill had the lead at the break, Jones again firing in after cutting in from the flank.
The away side took control after the interval, Kurtis Henderson showing tidy footwork in the box before firing in for 4-2.
Seamer's top-scorer Danny Glendinning had the perfect chance to make it 4-3 when he was brought down in the box by Edgehill keeper Chris Ferrey, but he smashed the resulting spot-kick against the bar.
Edgehill took advantage and Kieran Link made it 5-2 with the goal of the game, the midfielder beating Wood with a clinical strike after Aaron Jenking pulled the ball back for him.
Seamer rallied and grabbed a consolation through Kris Tate's free-kick, but the result had already been put beyond any doubt.
Clegg singled out Jackson Jowett as his side's star man, while keeper Wood was Seamer's man of the match.
West Pier joined Edgehill in the last four after beating Division Two Scalby 5-3.
Sam Medd's Scalby side took the lead just two minutes in, former Pier man Craig Rackham with the tap in.
Gaz Thomas levelled up for Pier, but another former Pier man, Rob Speight, lashed in to hand the Otters a 2-1 lead.
Kev Oxendale's goal restored parity before Sam Garnett handed Pier the lead for the first time in the game just before the break.
The Division One champions improved after the break and raced into a 5-2 lead, Jamie Bradshaw with both second-half goals, before sub Callum Randerson grabbed a late consolation for Scalby.
Stand-in Pier boss Paddy Parke said: "Fair play to Scalby they played well and battled hard, but we edged it on chances created and deserved to win."
Sam Garnett was Pier's star man, while Scalby chief Medd singled out right-back Elliott Spurr and young goalkeeper Max Tadman as his side's standout performers.
Newlands are in the hat for the semi-final draw after a 3-1 win at home to Hunmanby United.
Drew McCoubrey's cross flew straight in after 10 minutes to hand Joe Hakings' side the lead, but scores were level at the break after James Pinder's leveller for United.
Park were the better side after the break though, and they led again just five minutes into the second half when Dan Freer headed in at the near post from Ben Luntley's corner.
Freer was on hand again to grab Park's third, tapping in after Luke Delve's square ball to wrap up a 3-1 win.
Hakings singled out Freer as his side's star man, while John Emmerson was Hunmanby's man of the match.
FC Rosette are the only remaining side left in the competition from outside the top flight after they beat Ayton 4-0 in their quarter-final.
Jonny Frame made a superb early save to keep Ayton out, and then the only goal of the first half came when Dane Robinson was brought down in the box and and Al Wray smashed home from the spot.
Robinson was then on the scoresheet after half-time, wriggling free from two Ayton markers before curling into the top corner.
It was soon 3-0, Wray again the scorer after chipping into an empty net following a poor clearance, before Simon MacDonald headed in to wrap up the scoring for the victors.
Rosette didn't single out a man of the match, following a superb team display, Ayton's man of the match went to Jaymaine White.
In the only game in Division One, Goal Sports pulled off a shock 3-2 win against Filey Town, battling back after falling 2-0 behind.
Goals from Phil Dickens and Ricky Tomlinson put Town 2-0 up, and with only 20 minutes left on the clock it looked like Goal Sports were well beaten.
Jake Adams was shifted from centre-back into midfield and he quickly turned the game on its head, scoring a superb solo goal to half their deficit after 70 minutes.
Mike Beeby rifled in an equaliser after Tim McKnee's knock down, before Adams fired in to seal a dramatic turnaround and hand Mark Plumpton's side the points.
Adams was named as Goal Sports' man of the match.