Nathan Caine, Jason Law and Tyrese Sinclair all scored in the opening 35 minutes during a dominant first half for Stags .
Richard Cooper’s men then comfortably help on in the second half to seal an impressive win.
Caine got the scoring under way on 20 mins after heading in a Sinclair corner.
It was 2-0 five minutes later when Law volleyed home after a corner was only half-cleared.
Sinclair made it three after he rounded the keeper following a good pass by Caine.
Stags continued to create chances after the break with Sinclair going close once more after Harry Charsley, played him in.
George Shelvey was called into action as Taylor went through on goal, but the on-loan Nottingham Forest shot-stopper produced a fine save with an outstretched boot.
Mansfield then made their first change as Taylor Anderson replaced James Clarke, two minutes before James Gale recorded his first outing in Stags’ colours.
Sunderland had appeals for a penalty waved away by referee Garreth Rhodes when Harrison Sohna struck into the midriff of Keaton Ward.
Benjamin Kimpioka had a late opportunity to reduce the deficit but blasted over the bar after beating his man.
Next up in the competition is a trip to Wigan Athletic U23 on Thursday 28 October.
STAGS XI: Shelvey (GK), J. Clarke (C) (Anderson 69’), Cooper (Deakin 89'), Ward, Burke, Stirk, Charsley, Law, Sinclair, Bowery, Caine (Gale 71’).
UNUSED SUBS: Mason (GK), Hill.
SUNDERLAND XI: McIntyre (GK), Richardson, Dyce (Newall 67’), Wilding (C) (Wearne 46’), Younger, Jessup (Scott 46’), Kachosa, Sohna, Harris, Kimpioka, Taylor.
UNUSED SUBS: Carney (GK), Almond.
REFEREE: Garreth Rhodes.
ASSISTANTS: Daniel Guest & Danny Jarvis.
FOURTH OFFICIAL: Matthew Jackson.