Dave Hoole’s first game in permanent command ended in a controversial 2-1 defeat at Shaw Lane.
The Ducks’ winner came in the eighth minute of nine minutes of time added on — with Matlock wondering where the lengthy injury-time came from.
Kieran Wallace put Matlock in front midway through the second half only for home skipper Spencer Harris to head in twice, equalising on 86 minutes, to rob Matlock.
Harris had scored the only goal at Matlock earlier in the season.
Shaw Lane needed a win from the final game of the Evo-Stik NPL campaign to have a chance of making the play-offs, but victories for rivals Grantham Town and Farsley Celtic scuppered their hopes.
Matlock outplayed the promotion hopefuls for long periods.
There was a sharp contrast in styles with Matlock’s smooth and silky passing often opening up the home back line, while Shaw Lane relied on brute force and a largely route one approach.
Youngster Zak Brunt, yet to take his GCSEs, came into the side and had an excellent game, constantly a danger on the right.
Matlock probably should have made more of their first half opportunities.
Harry Limb, whose pace was an ever present threat, did well to bring down a cross from Jake Phillips but volleyed wide on 12 minutes.
Brunt then latched on to a poor clearance from keeper Eddie Wilczynski to feed Ricky German, whose low shot was deflected off the line by Kelvin Lugsden.
Jake Green went close in the 29th minute, firing narrowly wide of the far post after German left a Phillips cross from the right.
Harry Limb thought he would score but Wilczynski produced a terrific block save to keep out a powerful strike.
Matlock found the breakthrough in the 64th minute when Skelton and Wilczynski got in a terrible muddle and Kieran Wallace slotted into an empty net from the edge of the area.
But on 86 minutes Harris rose to head a Kieran Lugsden centre from the right past the diving Richard Walton.
Former Alfreton striker Paul Clayton headed wide at the far post from another centre.
It looked as if honours would finish even but the Ducks won a corner and Harris headed in to give Shaw Lane three undeserved but, in the end, meaningless points. Matlock finished 15th.
SHAW LANE: 1 Eddie Wilczynski 2 Jake Picton 3 Ben Gordon 4 Kelvin Lugsden 5 Jake Skelton ( 12 Paul Clayton 67) 6 David Norris 7 Alex Byrne 8 Spencer Harris 9 Keiran Lugsden 10 Damien Reeves (14 Chib Chilaka 60) 11 Godwin Abadaki (15 Gavin Rothery 60) Other subs: 16 Matty Davies 17 Ryan Serrant.
MATLOCK TOWN: 1 Richard Walton 2 Jake Phillips 3 Jake Green 4 Joe Doyle-Charles 5 Adam Yates 6 Dwayne Wiley 7 Zak Brunt (17 Jamie Jackson 58) 8 Kieran Wallace 9 Ricky German (16 Chris Ondong-Mba 72) 10 Ted Cribley (12 Harry Wood 90) 11 Harry Limb Other subs: 14 Amos Kabeya 15 Billy Whitehead.
REFEREE: Nik Storey (Manchester).
BEST GLADIATOR: Jake Phillips.