Nelson stole a point in their topsy-turvy Hallmark Security First Division fixture against Chadderton at Little Wembley as both sides finished with 10 men.
Samuel Dickinson gave the home side the lead in the third minute but Ryan Shenton equalised for Chadderton before the game had hit the quarter-of-an-hour mark.
The visitors then took the lead through Jordan Butterworth midway through the first half, an advantage they held until the closing seconds.
Nathan Webb came out second best in a one-on-one, Dickinson fired over and Jake Lloyd’s header dropped wide of the upright as the Admirals probed without reward.
Full back Alexander Grice fired straight at the keeper in the second half while substitute William Harris squandered a good opportunity when missing the target with just Jordan Hudlow to beat.
The away side lost their striker and manager David Fish following a heated dispute and Kieran Demaine suffered the same fate later on for a second bookable offence.
With time running out the Blues were awarded a penalty and Lloyd converted from the spot to secure a 2-2 draw.
Nelson, though, were knocked out of the Lancashire FA Challenge Trophy after a 5-1 defeat to Atherton Collieries at Victoria Park.
Webb put the hosts ahead in the second minute but Jordan Cover’s double swung the game in Atherton’s favour.
Vinny Bailey, Luke Giverin and Adam Farrell then rounded off the scoring.
Steve Cunningham’s side travel to the Mechanics Ground on Saturday to take on AFC Blackpool.