Chesham were leading through a sixth minute Barry Hayles effort when the lights partially failed with only 15 minutes played.
Hitchin Town moved into third place, level on points with second-placed Slough Town, after a 1-0 win at Causeway against bottom-markers Cinderford Town.
The struggling Foresters made it tough for the Canaries, who finally won it thanks to Matt Lench`s 13th minute goal.
There was a derby at the Premier Plus Stadium between another struggling and now managerless St Neots Town side and neighbours St Ives Town, who came into the game on an unbeaten run of six matches.
And it ended up being an emphatic win for the visiting Saints, who were only promoted at the end of last season and are now twelfth in the table.
Few at the beginning of the season would have predicted that St Ives would finish above an ambitious St Neots outfit, who are now ten points adrift of their Cambridgeshire rivals.
The visitors took the lead in the 19th minute through Liam McDevitt. St Ives doubled their lead on the half-hour mark when Ben Seymour-Shove`s cross was headed home by Danny Kelly.
Seymour-Shove went from creator to scorer four minutes before the break when beating St Neots `keeper Alex Archer from fully 30 yards. And ex-St Neots midfielder Josh Dawkin made it 4-0 just six minutes into the second period with a superb volley past Archer.
Tuesday`s other game between Stratford Town and the team who came up with St Ives, Kings Langley, ended in a 2-2 draw in Warwickshire.
Kings have struggled since the departure of their joint-managers Richie Hanlon and Paul Hughes to league rivals Hayes & Yeading United and hadn`t won in the league in six games heading into this one.
And when Ben Stephens put Stratford in front inside two minutes, it didn`t look good for the Hertfordshire outfit. But 10 minutes later, Ryan Plowright equalised and 10 minutes after that, Jeremiah Amoo put them in front.
They held that lead right until the third minute of stoppage time at the end of the game when Justin Marsden popped up with Stratford`s leveller.
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