A disappointing second-half performance saw the Bulls edged out of the Nottinghamshire Senior Cup by Carlton.
Goals in the second period from Kieran Walker and Oliver Clark sealed the Millers' place in the semi-finals, before Jack Broadhead saw a late red card for AFC, their third red card in seven games in all competitions.
The Bulls were well on top in the first half and had enough chances to go ahead before the break, but their hard work was undone when Kieran Walker knocked a free-kick home past Tom Crosby.
The hosts looked the better value in the second half, and deservedly found the goal which confirmed their place in the final four with just a few normal time minutes remaining, with Oliver Clark heading home Walker's throw-in.
Matters went from bad to worse for the Bulls when defender Jack Broadhead saw a straight red card for a late challenge on Millers 'keeper Jack Steggles.
AFC are now fighting on just the one front - perhaps with good reason - as they look to secure their Evo-Stik League status, with a trip to Belper Town up next on Saturday.
MATCH DETAILS
Final score | Carlton Town 2-0 AFC Mansfield
Scorers | Walker (50'), Clark (87')
Carlton Town XI | Steggles, Ebanks, Davie, Moore, Clarke, Walker, Clark, Bertram, Stovell (Hutchinson 83'), Opoku (Blake 83'), Motshweni
Unused substitutes | Rollinson, Robinson, Frost
Yellow cards | N/A
Red cards | N/A
AFC Mansfield XI | Crosby, Marsden, Annable, Lindley (C) (D'Laryea 76'), Lawrence, Broadhead, Dawes (Dear 63' (Buxton 92')), Ghaichem, Fearon, Wall, Ward
Unused substitutes | Dudley, White
Yellow cards | N/A
Red cards | Broadhead (89')
Man-of-the-Match | TBC
Attendance | TBC