The Japan winger marked her return from the Asian Cup, where she scored four goals for her triumphant national team in Australia, to secure a 1-0 success at bottom side Leicester City.
Her 49th-minute finish took her to seven WSL goals this term
Seike only returned to training with her club in midweek along with compatriot Moeka Minami. Both played the full 90 minutes at the King Power Stadium.
It was the Seagulls’ first league win in five games and takes them into the top half of the table ahead of a tough run which sees them face both Manchester clubs as well as Arsenal.
Albion went close very early on when Caitlin Hayes’ close range header from Fran Kirby’s corner was blocked by home goalkeeper Janina Leitzig.
Maisie Symonds curled a free-kick narrowly wide as Albion made the early running.
The fact Leitzig, who was not required to make a save on that occasion, then went down asking f-r treatment suggested Leicester felt they needed a tactical rethink.
Seike headed well wide when Madison Haley chipped a ball into the box.
Symonds intercepted a loose pass out by Leitzig but, from long range, could not send her shot past the retreating goalkeeper.
Leitzig then dived to push away a shot by Haley which had been slowed down by a deflection as Albion worked the ball cleverly through Fran Kirby.
And Rosa Kafaji sent a low shot straight at the keeper.
Albion found more cutting edge to go ahead in the 49th minute.
Kirby threaded an expert pass inside the full-back and Kafaji got in behind to tee up an open goal for Seike.
Kafaji was later denied by a goal-saving block after a similarly slick move involving those same three players.
Seike saw an effort deflect narrowly wide.
And Leitzig parried a Seike blast after more inventive work by Kirby.
She also saved a clever curler from the excellent Kirby in the dying moments.
Leicester belatedly managed a flurry of pressure and forced two corners, the first of which saw Chiamaka Nnadozie make a soaring claim.
But the Albion goalkeeper generally had very little to do as her side turned in a professional performance on the road with just enough end product.