The Rebels got off to the worst possible start against the Hertfordshire side, conceding after just two minutes. A simple long pass played forward was allowed to bounce, with Ryan Lake leaving the ball for debutant goalkeeper Billy Granger, but striker Tobi Akinjirrin capitalised on the confusion by nipping in and poking the ball into the bottom corner.
Akinjirrin would continue to pose all sorts of problems to Slough’s uncertain defence, but the Rebels almost found an equaliser, with goalkeeper George Kamurasi making a good block from Dyer as Slough got in behind the visitors for the first time.
Potters Bar twice went close to extending their lead, first through striker Josh Hutchinson, who saw a penalty appeal waved away before testing Granger with a strike at the top corner, forcing the keeper into a fine save.
Winger Finbar Robins then went close, coming inside and blasting a shot inches over.
For Slough, Dyer looked the most likely to score, and he went close as he stretched to meet a cross to the far post, whilst the returning Eddie Smith, thrown straight back into the starting eleven, was denied by Kamurasi, the keeper making another of a string of fine saves.
The game swung from end to end, with Lake putting a free header wide from a corner, and Akinjirrin back-heeling for the dangerous Robins to drill just over again.
With half an hour gone, Slough conceded the first of two quick-fire goals as the match looked to be put beyond them. First, Guy Hollis mistimed a sliding tackle on the slick surface and felled Robins for a clear penalty. Akinjirrin stepped up to confidently send Granger the wrong way from the spot.
Just two minutes later, Slough again struggled to cope with the movement of Akinjirrin and Hutchinson, and the latter found himself free on the edge of the box to shoot past Granger into the top corner to put Potters Bar three goals ahead.
Slough needed a quick response, and the skipper provided it three minutes later, climbing highest in the middle of the penalty area to head a Darren Wheeler free kick delivery past Kamurasi.
Warren Harris twice went close to pulling back another goal, Kamurasi again demonstrating his shot-stopping abilities by turning away a volley and getting behind another fiercely-struck shot. But on the stroke of half-time, Slough did get a crucial second goal as Dyer headed in from Wheeler’s corner.
This goal proved to be vital as Slough immediately set about finding an equaliser in the second half. Wheeler saw a strike comfortably saved before Kamurasi turned another header from Dyer behind.
Wherever possible, Wheeler and Warren Harris tried to whip crosses into the box to test Kamurasi, and Slough went close through Warren Harris and Wheeler again as a third goal looked certain to follow.
Slough were rewarded for their persistence when, on 70 minutes, Dyer stooped to head in a Wheeler cross at the far post, with Kamurasi unable to prevent the ball going in via the underside of the bar.
The Rebels continued their relentless pursuit of a fourth to seal all three points, but were highly fortunate it did not go the way of the visitors, as Hutchinson wasted a clear chance. But with five minutes remaining, Dyer scored his third and Slough’s fourth to cap a remarkable comeback. Potters Bar stood off Smith on the right, and the striker lifted in a cross which Dyer headed down past Kamurasi, with the ball nestling in the bottom corner.
Potters Bar Town Line up
George Kamurasi, Ashley Harrison-Barker (c), Lewis Impleton, Ben Bowditch, Fabian Simms, Tom Proudlock, Finbar Robins, Bradley Wadkins, Tobi Akinjirrin, Josh Hutchinson, James Ewington. Subs: Cole Penny, Dan Millard, Frankie Lane, Skan Grace.