Bishop's Stortford suffered a 3-1 home defeat to promotion rivals Harleston Magpies II on Saturday as the battle to go up to the National League intensified.
It was a second successive loss for leaders Stortford, who are now top of the East Women's League, Premier Division only on goal difference ahead of Norwich City after their closest challengers triumphed 6-1 at bottom side Ipswich & East Suffolk.
And Harleston, who sit third, are now just two points behind Stortford with six games of the campaign remaining.
The away side took the lead in the first minute before doubling their advantage with only 10 minutes gone.
Stortford rallied and went close through Lexi Guthrie before Abbie Barrett pulled a goal back just before half time.
The hosts dominated the opening exchanges of the second period and almost equalised with efforts from Livvy Smerdon and Barrett.
More short corners followed and further chances were created in open play, but Harleston were dogged in defence and put the game to bed with a goal on the break 10 minutes from time.
Stortford goalkeeper Ali Martyn made a series of fine saves to prevent a wider margin of defeat.
The leaders' next two games are against sides in the bottom three before they visit second-placed Norwich City on March 5.
Emma Hynds and Suzanne Holmes struck as Stortford II ground out a 2-1 win at Shefford & Sandy in 2SW.
Captain Hynds found the net with a ferocious short-corner shot before Holmes found the bottom corner having evaded several desperate tackles.
The hosts pulled a goal back from a penalty stroke and had a last-minute equaliser disallowed as fourth-placed Stortford, for whom Anna Sydes was player of the match, held on.
Stortford III registered a 3-2 success when they visited Saffron Walden II in 3SW. Vicky Cox, Jemma Pettit and Issy Hatfield were all on target, with the latter being named player of the match.
In the same division, the depleted Archdeaconesses were unlucky not to earn at least a point at Cheshunt as their opponents won the game with a late short corner.
Stortford V are still unbeaten in 2022 following a 2-1 home victory over Bedford VI in 5SW. The hosts fell behind early on, but Emma Cox levelled matters before Zoe Bovaird grabbed a last-gasp winner.
Mel Cassel Dummet got the only goal of the game in the second half as the Acolytes won 1-0 at Havering IV in 6SE.
She finished off a lovely passing move as they triumphed in one of their hardest matches of the season. Alana Baldwin was player of the match for a fantastic defensive performance.
Stortford VII took another step towards claiming the 7SW title as they came from behind to seal a 3-2 home win over third-placed Broxbourne V.
Caz Greenall scored twice – including the winner five minutes from the end – either side of a strike from Alison Chadwick to keep the runaway leaders nine points clear at the top.
Greenall, Chadwick and Mary Sanders all received equal votes for player of the match.