Market Rasen Town came up short in their showdown with fellow promotion hopefuls Barnoldby on Saturday.
Tom Avison, Callum Blythe, Joe Hart and Mark Moughton were all on target as the East Lincs Combination Division Three leaders made it five wins from five.
Rasen remained in third place after their first league defeat of the season, but fell five points behind Barnoldby and GB Kitchens, who also extended their 100 per cent record with a 10-1 hiding of Burgh Athletic.
* Brigg Town CIC booked their place in the second round of the Lincolnshire FA County Junior Cup with a narrow 2-1 win at home to Crowle Town Colts.
Brigg were made to work for their place in the next round of the competition, despite playing against 10 men for more than half the game.
As often the case this season, Brigg found themselves a goal down early on, but the Zebras top scorer Reece Moody equalised for his ninth goal of the season.
The Central Midlands side dug in and kept the hosts at bay for most of the second period, but substitute Jonathan Nicholls eventually found the winner to send his team into the hat for round two.
But Briggensians were not so lucky as they bowed out after a high-scoring match with Lincolnshire League side Lincoln Moorlands Railway.
Chris Nuttall’s goal, accompanied by braces from Robbie Smith and Jordan Woodward were enough to see Moorlands progress despite conceding three times in Brigg.