A lacklustre second half showing from Whitby Town ensured they fell to derby day defeat, Scarborough Athletic running out 2-1 winners.
Niall McGoldrick opened the scoring for the hosts, capitalising on poor Scarborough defending.
However, the tide turned in the second half, with Charlie Binns and Nathan Valentine netting free headers.
Further disappointment followed for Whitby, as David Carson was issued with a second yellow card after the full-time whistle for an argument with the referee.
John Campbell made his first start since returning from an ankle injury, replacing Anthony Hume in Chris Hardy's only change.
And it was the hosts who threatened earliest, Carson firing wide after Campbell found him in space with a neat through ball.
The visitors, however, did threaten, with Binns' curling an effort wide inside the penalty area, following up on Max Wright's fizzed ball across the face of goal.
Just moments later however, the Seasiders gained the initiative after looking clearly the better side.
McWilliams' inswinging corner was fumbled by nervous-looking Thomas Taylor, falling to Weledji who chipped onto the crossbar.
The ball fell into a sea of bodies, with Niall McGoldrick leaping highest to head home.
The game was pretty much one-way traffic, with Whitby creating a number of chances, most notable through Weledji, who saw his first-time chip tipped over.
Campbell forced a save low to Taylor's left, while ahead of the break, Carson fired a powerful effort in from 25 yards, though again Taylor was its equal.
Whatever Steve Kittrick said at half-time, reflecting on a poor first half for the Seadogs, must have been ringing in the ears of his players as they started the second half on the front foot.
It was the Blues who had the first chance of the period though, Campbell again threatening with an unexpected thirty yard drive just wide of the mark.
However, the more comfortable Seadogs pushed on and soon had their equaliser.
Substitute Billy Logan received the ball to feet from Jack Johnson. He turned his man with ease, sending a ball straight onto the head of Binns, who found the roof of the net.
It was almost two seconds later. Binns was again involved in the action, playing a ball forward for Coulson.
He sent a curling effort goalwards, but Shane Bland managed to get down well to get a hand to it.
Dave Merris soon tried his luck, as Whitby fell to pieces in the face of an Athletic onslaught, though Bland tipped his thirty yard effort over.
Whitby still tried to get their noses back ahead, against the run of play.
McWilliams' ball into the box found Steven Snaith at the back post, who headed across goal to force a smart save from Taylor yet again.
Whitby hearts were broken, just two minutes later, though.
More static defending became the Blues' undoing, as Max Wright's ball into the box found Valentine, who headed home unmarked into the bottom corner for the winner.
Hardy came out of the game with more bad news too, as Carson received a second yellow card after the full-time whistle for arguing with referee Christopher Ellis, meaning he'll miss next weekend's FA Trophy game against Marine.