Desborough Town lost ground on the top two in the ChromaSport & Trophies United Counties League Premier Division after a last-gasp goal denied them all three points at Newport Pagnell Town.
Ar Tarn looked to be on course for another win when Merson Styles scored with a free-kick with just six minutes remaining.
But the hosts earned a share of the spoils thanks to Adam Pryke’s goal in the final minute.
Rothwell Corinthians suffered a 5-1 home defeat to second-placed Eynesbury Rovers with Jed Downing grabbing their consolation.
Wellingborough Town, meanwhile, fought back from a goal down to earn a 1-1 draw from their clash at Peterborough Northern Star.
Whitworth’s fine form continued as they maintained their promotion challenge in Division One with a 4-1 victory over Oakham United at London Road.
Jonny Hazell scored twice while Remy Brittain and Jack Dyson added the others for the Flourmen.
Irchester United made it four wins in a row and moved into the top five as they leapfrogged Buckingham Town after a 4-1 success at Alfred Street.
Ty Clark, Matty Keenleyside, Dan Spaughton and and Nathan Heycock were on target for the Romans.
It was a day to remember for Stewarts & Lloyds as they moved off the bottom thanks to their second win of the season as they ran out 6-2 victors at fellow strugglers Woodford United.
Jake Buckingham hit a hat-trick for the Foundrymen while Alessio Mastrangelo, Harry Henbury and Shyti Donald added the others for Ian Benjamin’s side.
That result saw Burton Park Wanderers drop to the foot of the table after Raunds Town snatched a late winner at Latimer Park.
The Shopmates had led courtesy of an own-goal before Wanderers levelled and it looked set to end in stalemate until Jamie Russell secured Raunds a 2-1 success in stoppage-time.
Thrapston Town enjoyed a 2-0 victory at Long Buckby thanks to goals from Jedd Whiteman and Isa Ali but Rushden & Higham United were beaten 3-0 at Daventry Town, who moved back to the top of the table as a result.