Jordan Lee's Itis Itis Rovers side took the lead thanks to Ryan Megginson's strike, but scores were level at the interval after Danny Glendinning levelled for Seamer with a superb lobbed goal.
A fairly even contest ensued after the break, but it was Rovers who grabbed the spoils - Neil Forsyth putting them ahead with a superb left-footed strike before substitute Mikey Barker wrapped up the scoring for Lee's men.
Centre-back Callum Gravestock was Rovers' star man, while Joel Ramm was Seamer's man of the match, with 16-year-old keeper Alex Chapman also impressing on his debut.
Edgehill were made to work hard for victory in a 10-goal thriller against Scalby.
RETRO SPOTLIGHT: 15 nostalgic Scarborough photos from the Scarborough News sports archives
Scarborough Athletic slip to 2-0 defeat at Brackley Town in National League North opener
Commonwealth Games 2022: Scarborough's Chris Turnbull and Team England win bowls mixed para pairs bronze medal
Ebberston battle back to sink hosts Filey in SBL Premier Division thriller
Tokyo Olympics 2020: Scarborough's Charlotte Fry and Team GB win team dressage bronze
Sam Medd's Otters went ahead thanks to George Bramham's strike, but Danny Collins levelled matters up for Edgehill.
Scalby stunned Steve Clegg's side though as Rob Speight rounded the keeper to tap in for 2-1 before Lewis Tadman's smashed in a stunning long-range strike to hand the visitors a 3-1 lead at the half-time break.
A contentious penalty was awarded to Edgehill just minutes into the second-half and Sean Exley slotted in for 3-2 and the momentum was with Clegg's charges.
It was soon all-square again when Joe Gallagher netted before a Jamie Patterson effort put Edgehill 4-3 ahead.
A late brace from Tyson Stubbings and a Ryan Link strike wrapped up a 7-3 win for the champions.
Clegg was pleased with his entire side's efforts, especially as they rallied back in the second half, while Scalby boss Medd was also delighted with his team's performance.
West Pier won 4-2 on the road at Filey Town.
Simon Reeves netted the first for Will Jenkinson's Pier side after Steve Sheader headed a corner back across goal for him to scramble the ball over the line.
Two quickfire goals from Martin Cooper then put Pier in full control at 3-0 to the good.
Filey fired back through Harry Ward to make it 3-1 at the break and give themselves hope of a second-half comeback.
Any aspirations Filey had of battling back into the contest were ended when another Pier corner ended in a goal for Jack James after Jenkinson's nodded effort was cleared off the line.
Town grabbed a consolation through Jordan Philliskirk, but the damage had already been done.
Two-goal hero Cooper was Pier's man of the match with Reeves, James and Mikey Pickering also impressing, while stand-in keeper Billy Coyne stood out for Filey.
Ayton v Hunmanby United was postponed due to a waterlogged pitch.