Desborough Town claimed the local bragging rights as they won 2-1 at Wellingborough Town in the ChromaSport & Trophies United Counties League Premier Division.
All the goals came in the second half as Mark Redding and Jake Bettles put Ar Tarn 2-0 up.
An own-goal from Josh Kisby gave the Doughboys hope late on but Desborough held on to move above their rivals in the table.
It also proved to be a great night for AFC Rushden & Diamonds, even though they weren’t playing.
The leaders’ nearest rivals Wisbech Town were beaten 2-1 at Peterborough Northern Star in what was their game in hand on Diamonds.
It means Andy Peaks’ side go into their home clash with the second-placed Fenmen on Saturday with a four-point lead and have the opportunity to pull clear with a victory.
The Division One local derby went the way of Rushden & Higham United as they won 2-0 at Burton Park Wanderers.
Jordan Pendered’s goal set the Lankies on their way and the win was confirmed by Jory Mann’s goal on 65 minutes.
Raunds Town fought back to hold high-flying Potton United to a 1-1 draw at Kiln Park.
Gary Ansell-Carter gave the visitors a first-half lead but Karl King earned the Shopmates a point from the penalty spot after the break.
Irchester United became the latest side to fall to leaders Northampton Spencer who made it 21 games without defeat with a 5-0 success at Alfred Street.
The teams were only separated by Mitch Blande’s own-goal at half-time but Spencer ran away with it in the second period thanks to a brace from former Roman Ryan Lovell and further efforts from Paul Pickering and Deanio Bailey-Browne.
Thrapston Town, meanwhile, went down 4-1 at Bourne Town, who took a 2-0 lead through Henry Dunn and Josh Hales.
Jack Wisniewski threw Thrapston a lifeline after the break but further goals from Hales and Harley Williams secured the home win.
Don’t miss more news from the local United Counties League teams in Thursday’s Northamptonshire Telegraph