Southgate Harmen blew the Division One promotion race wide open as a late wonder strike from Ben Murrell saw them leapfrog Neasden in the race for promotion.
Neasden had only themselves to blame as they failed to build on a good start given to them by leading scorer Ryan Sher. They paid the penalty as goals by Craig Phillips and Murrell means Harmen can go four points clear in second if they beat Oakwood on Sunday.
Harmen manager Dan Uzan said: "After the way that we lost last week against Brady, this was the perfect response. We competed exceptionally well considering we had a depleted squad.
"I think we will definitely come third provided we beat Oakwood. Any higher? Who knows." However, he admitted that his squad would "struggle to compete in the Premier Division" if they gained promotion.
Both teams were missing key players for this crunch clash in which Neasden needed a point to confirm promotion. Neasden were missing Ben Wulwik and Danny Daggers, while Harmen were without Ziggy Lichman, Lee Hyams and Lloyd Becker.
Neasden shaded the first half. They forged ahead on 18 minutes when Stevie Krein's free-kick was spilled by stand-in Harmen keeper Hal David, allowing Sher a simple tap-in. Harmen equalised against the run of play on the half hour when a free-kick from Jonathan Hirshler was neatly slotted past Ed Bloom by Phillips.
The second half saw Harmen come out the stronger and only a brilliant goalline clearance from Rob Bloch denied Ben Forman who went close with a chip minutes later.
Neasden had chances to level with Sher heading wide and then denied by a brilliant finger-tip save by David.
This proved crucial as 10 minutes from time a break-away saw Murrell show brilliant control before in one movement crashing the ball in off the far post to bag a dramatic win.
There was still time for a late twist but Adam Klein blasted a shot wide from 10 yards. Neasden joint-boss Sammy Carr was fiercely critical of his side, who started the day looking to take a step towards the title, but now face an anxious fight to win second place.
"I told the players that we needed to press Southgate but we didn't do it. They had too much time to play and we were punished for that," said Carr.
"We now have a nervous end to the season, but it's a long campaign and there's still a while to go. We need to win two of our last three games to ensure promotion, but I'm glad that we are playing in the Morrison in our next match and not the league as it given us another focus."
Harmen: David; Lesner (sub: Knofo), Morris, Hecht, Webber; Hirshler (sub: Bourne), Murrell, Taylor, Phillips; Forman, Avital
NWN: Bloom; Lester (sub: Springer), Bloch, Bookbinder, Klein; Frankel, Hodes (sub: R Glynn), Krein; Bowman, Sharp Sher