A fine finish from Alex Bradley and late Jack Emmett effort ensured Town overcame Eastleigh at The CNG Stadium to progress into the last eight of the FA Trophy.
Simon Weaver made six changes from last weekend's trip to Aldershot and handed first Town starts for centre back Maxim Kouogun and 17-year-old forward Kian Harratt.
Town created the first chance of the afternoon after good play down the right wing involving Brendan Kiernan and Ryan Fallowfield, but Jack Diamond could only head the full back's delivery wide.
George Thomson was the next to have a headed attempt on goal, but like Diamond couldn't find the target, with the Sunderland loanee providing the cross on this occasion.
Diamond continued creating chances for his side, teeing up Harratt next who was desperately unlucky to see his finish hit the inside of the post and bounce clear, denying the striker a first senior goal.
Town's early pressure eventually paid off in the 23rd minute as Bradley played a one-two with Harratt before bending the ball first time into the top right corner.
Eastleigh did manage to muster their first shot after going behind, but failed to trouble Joe Cracknell as Town went into the break a goal to the good.
Town came out of the blocks in lively fashion for the second half as Harratt, fed by Diamond, saw his early effort fly over.
Weaver's side were enjoying plenty of possession, but struggling to break down a disciplined defence, Fallowfield combining with Kiernan to force a save from Ryan Flitney just past the hour mark.
Town struck woodwork for a second time in the 78th minute, Kiernan darting and front of his man and turning substitute Jack Emmett's low cross onto the upright.
Eastleigh had a golden chance for an equaliser eight minutes from time as the ball dropped kindly to Jake Scrimshaw, but the substitute blazed over the bar.
Ben Strevens' side would rue the missed chance as Emmett put the final nail in the coffin in the 86th minute, applying the finish after Kiernan's low cross had deflected into his path to send Town into the last eight.
Harrogate Town: Cracknell, Fallowfield, G Smith (Gallacher 90), Burrell, Thomson, Kiernan, Bradley, W Smith, Diamond (Emmett 71), Harratt (Muldoon 72), Kouogun
Subs not used: Belshaw, Stead, Kerry, Hall
Goals: Bradley 23, Emmett 86
Eastleigh: Flitney, Partington, Boyce, Payne (McKnight 68), Rendell, Smart, Bearwish (Scrimshaw 77), Wynter (Green 35), Miley, Alabi, Godwin-Malife
Subs not used: Stryjek, Barnett, Hollands
Referee: S Copeland