Sitting top of the NWC First Division after three successive wins, Nelson were given a wake-up call on Saturday.
The Blues, looking to maintain their unbeaten home record, made two enforced changes, as Jake Lloyd came in for the suspended Ashley Mihell and Jonny Hession replaced Nat Taylor, out with a broken leg.
The early exchanges were even, but the Admirals had the first shot in anger when, from a corner, the ball was cleared to Richie Allen, but his first-time effort went tamely straight to keeper Jamie Brewer.
Against the run of play, a defensive mistake let in Jordan Icely to put the visitors ahead on 17 minutes.
Nelson pressed hard for an equaliser, but they were soon 2-0 down as Graham Mooney raced away down the right and beat Ben Woodhead with an angled drive.
Mark Fell’s men pulled one back before half-time when, from a quick throw in, the ball was threaded through to Peter Wright, who lobbed Brewer from 20 yards.
Nelson started the second half on the front foot, with Wright having a number of chances, and they were made to pay for their profligacy when Gary Prescott strode through to make it 3-1.
Liam Boswell scored a fine individual goal to cut the deficit again, but two late goals from Simon Whitehead and Prescott sealed the Blues’ fate.
Tomorrow they face a tough trip to Hanley Town, before hosting Rochdale Town on Wednesday.