Scarborough Athletic sent out a message to the Evo-Stik North on New Year's Day as they did a job on title favourites South Shields.
Boro were better, battled harder and took their chances in a 3-1 win that ended Shields' unblemished record at Mariners Park.
Much of the success centred around Boro's pressing and the tactical move which saw Nathan Valentine shadow former Premier League man Julio Arca around the field.
But in the early passages it seemed a long afternoon lay ahead for Boro, as Shields assumed control.
Matty Pattison could have put a completely different complexion on things, but he scuffed wide when well placed.
Then Dave Merris managed to clear the danger after a swift piece of interplay around the Boro box.
Boro soon began to take a foothold though, with Shields and their supporters getting more and more frustrated by the shift in power.
James Walshaw saw his effort cleared off the line by Jon Shaw as Boro got closer and closer.
But there was still plenty of danger at the other end, much of which was based around Gavin Cogden.
The striker almost gave Shields the lead just before the half-hour when he collected out wide and drove incisively into the box before crashing into the side netting.
Boro looked to have been hit by a blow soon after this when an injured James Cadman was withdrawn to be replaced by Lewis Sugden.
But within a minute Boro were ahead.
Michael Coulson had too much ability for Liam Connell as he jigged into the Shields box and the keeper brought him down.
Coulson dusted himself down and compounded Connell's agony by sending him the wrong way.
Boro maintained their pressure and Shields continued to crack.
After Coulson had drilled into the side netting, Valentine rose brilliantly and powered a header into the bottom corner of the net.
Walshaw then had two good chances to add a third of the afternoon before the interval.
The dangerous striker leapt above Connell, but flicked his header an inch wide. Then he found a gap of space on the edge of the six-yard box after a melee, but his shot hit the post.
Boro had to put on their tin hats when the second half got underway, but they survived another onslaught led once again by Cogden.
After soaking up this pressure, Boro struck for a third time.
Sugden whipped a lovely ball into the Shields box and Max Wright nipped in to head home.
Boro's fans were buzzing, but they still had plenty of nervous moments in the remaining half hour.
Having thrown on former Whitby Town goal-machine Graeme Armstrong, Shields began to switch through the gears.
Another sub Carl Finnigan should have trimmed the lead when he collected on the penalty spot, but with the goal at his mercy, he shot wide.
Then Armstrong headed over from just a handful of yards when it seemed much easier to score.
Boro still had their chances to add to their tally, both Coulson and Valentine going close with efforts from distance.
A flashpoint followed with 10 minutes remaining as Finnigan clearly struck Valentine in the face after an argument. Referee Lindsey Robinson consulted her linesman and between them they lacked the bottle required to dismiss the Shields attacker and he was given a stay of execution.
Bailey Gooda made another superb saving tackle, before Shields finally managed to get themselves on the scoresheet in the last few minutes.
Boro failed to deal with Arca's chip into the box and Jamie Holmes flicked home.
The visitors saw off a few more Shields raids after this and they completed a fine smash and grab victory that blew the promotion race wide open.