James Dean, Lee Gregory and Jamie Vardy all scored twice as top of the table Town ran riot against their relegation threatened West Yorkshire neighbours.
There was no hint of what was to come in a sluggish opening 20 minutes that saw the Shaymen give the ball away all too often.
And even when they took the lead through Dean they allowed the visitors to level within a couple of minutes.
But they opened up a 4-1 interval lead and were in cruise control after the break, content to double their tally to record an emphatic win.
The combination of Simon Garner, Scott Phelan and Aaron Hardy almost opened up the Ossett defence inside the first minute.
And a couple of long balls, the first by Danny Lowe, the second from Phelan, might have got Gregory in but he could not get a touch to the first and was unable to bring the second under control.
A poor Ossett free kick apart, it continued to be a game of attack against defence with the Shaymen well on top.
Gregory set Lowe away on the left then almost got on the end of the full back's cross, and a Gregory ball in from the right flew just over Dean's head.
Surprisingly, it was the visitors who forced the first corner of the game and when the ball was worked back to Caldon Henson he struck a shot with the outside of his right foot that flew just over the bar.
Ossett looked every inch a team in deep relegation trouble and, at times, struggled to get the ball out of their own half.
But Town were not at their sharpest either, as the players were reminded on more than one occasion by manager Neil Aspin.
So lethargic were they that Ossett almost capitalised as they failed to spot the run of Nathan Kemp from a James Riordan free kick and the defence was relieved to see a diving header flash wide.
Moments later, Jonathan Hedge was forced into a smart save from a Jordan Hatton shot and from the resulting corner Daniel Facey turned the ball goalwards and Hardy was forced to clear off the line.
It took Town time to recover but they might have opened the scoring after 25 minutes when Hardy fed Dean on the right and his low cross reached Vardy but he fired across the face of goal and wide.
A minute later the Shaymen were in front and Vardy was the provider from the right with Dean pouncing to fire home from close range after Ossett Keeper Neil Bennett had only parried Phelan's effort
The lead lasted just two minutes as Ossett forced a corner which Hatton took and David Boardman turned home.
Ossett were made to pay for scoring their goal as Town took a firm grip on the game before the break.
Vardy had a glorious chance to put Town ahead again after 33 minutes when he latched onto Simon Garner's long ball, but again he pulled his shot wide of goal.
Dean made no such mistake two minutes later from a Gregory flick as he controlled the ball on his chest with his back to goal and, despite an awkward bounce, wrapped his left foot round it to smash home.
And two minutes before the break Gregory gave the Shaymen a two goal cushion when he slid in to score after Vardy had done well to regain possession on the right and fire in a low cross.
And it got even better as the 45 minutes came to an end when Hardy found Dean whose short pass forward gave Vardy time and space to fired the fourth between the keeper's legs.
Danny Holland replaced Dean at the break and he almost got on the end of a Garner cross within 90 seconds of the restart.
Town bagged their fifth goal of the night after 50 minutes and the ball went in twice.
Baker fed Vardy on the left and his low cross was deflected goalwards by a defender. The keeper clawed it back, although it looked like it had gone in, then Phelan made sure, even though the linesman in front of the main stand was not certain despite the ball being a good yard over.
The same linesman failed to react when Holland was clearly impeded by a defender as he tried to get into the area to capitalise on a weak back pass.
The Shaymen carved open the visitors' defence again after 56 minutes, Vardy finding Holland whose square ball was perfect for Baker racing into the box, but he swung at fresh air.
And they had the ball in the net again just past the hour when the linesman flagged for offside against Gregory even though he had no part in the play as Phelan raced through to blast home.
But they only had to wait until the 66th minute for the sixth Town goal of the night, Gregory bagging his second as he walked the ball round the keeper and fired home after Holland had been tackled on the edge of the area.
And they almost had another minutes later when Garner cut in from the right and sent a left footed effort flashing narrowly wide.
The Shaymen bagged their seventh with a flowing move down the left, Holland releasing Vardy who looked up and squared for Marshall who slammed home.
And two minutes later it was 8-1, Marshall racing down the right and returning the favour as Vardy collected his pass and rounded the keeper before rolling in.
Bennett denied Town a ninth two minutes later when he tipped a thunderous Holland shot onto the post then recovered to save from Vardy on the rebound.