AFC Rushden & Diamonds were sent tumbling to only their second league defeat of the season as two goals in the final six minutes saw them beaten 2-1 at Thurnby Nirvana in the ChromaSport & Trophies United Counties League Premier Division.
Diamonds will be at the summit on Christmas Day but their lead was cut to eight points after a stunning fightback from the hosts.
After a goalless first half, the leaders appeared to be heading for another victory when Richard Bunting put them in front after 56 minutes.
But Thurnby equalised with six minutes to go when Ash Day converted from the penalty spot.
And the hosts won it in the second minute of stoppage-time through Celson Patricinio.
Wellingborough Town squandered a 3-1 lead as Sleaford Town fought back to win 5-3 at the Dog & Duck.
Jon Mitchell gave the Doughboys the lead and Jake Newman doubled the advantage from the penalty spot.
Ryan Parnell pulled one back for the visitors but Dan Spaughton made it 3-1 on 55 minutes to keep Wellingborough in control.
However, Liam Tunstall struck almost immediately before Euan Clarke equalised.
Parnell’s second put Sleaford in front for the first time and Clarke completed their victory two minutes from the end.
It was a day to forget for Desborough Town as a torrid first half saw them beaten 4-0 at Deeping Rangers.
Ar Tarn found themselves 3-0 down inside seven minutes thanks to Jordan Avis and a double from Jezz Goldson-Williams.
And the scoring was rounded off in first-half stoppage-time when Goldson-Williams completed his hat-trick.