Nelson’s unbeaten start was ended in the battle of first against second on Monday night.
The Blues went to Atherton Collieries with seven points from a possible nine, and things looked promising at the break, with the Admirals leading 1-0.
Seven minutes from the interval, Nick Murphy crossed for Nat Taylor to stab home at the far post to give Nelson a deserved lead.
However, after controlling the majority of the game, Mark Fell’s side began to look vulnerable in the final quarter.
Just after the hour, Ben Woodhead kept out Jake Patton’s shot at full stretch, but Mark Truffas was on hand to turn in the rebound.
And 20 minutes from time, Paul Atherton netted the winner after a defensive mix-up.
On Saturday, Nelson’s 100% start was ended in a 2 - 2 draw at home to Chadderton.
Chadderton were the better team in the first half,and went ahead on 32 minutes as Matthew Russell turned in a right wing cross.
Two minutes later Nelson levelled as a corner from Liam Boswell was headed in by Josh Barrick. Nelson bossed the second period, and went in front three minutes in as Boswell drove at the defence before lashing a superb effort home.
The Admirals pushed for a third goal, but midway through the half, Niall Sultan was brought down by Tom Anderton and Russell sent Woodhead the wrong way from the spot.
Nelson are at 1874 Northwich in league action tomorrow.