Alex Smithies produced two late saves to steer Huddersfield into the FA Cup fourth round – and then denied speculation he could leave this month.
The England under-21 prospect has hit peak form in recent weeks, sparking rumours of a big-money move to the Premier League.
Town boss Lee Clark – who labelled Smithies after the game as a "future international keeper" has said none of his stars will be sold including his prized keeper and Anthony Pilkington.
Smithies, 20, denied all knowledge of any reputed interest in his signature and said: "I don't read the newspapers. I am just concentrating on doing my best for Huddersfield Town and if the manager says I am not leaving, that's the end of it."
Smithies, redundant for much of the game, was only called into action in the last 10 minutes.
He pulled off a fine stop from Dover's 29-goal striker Adam Birchall and then two minutes from time spared the blushes of Antony Kay who feared an own goal after he deflected Harry Baker's shot goalwards.
Smithies said: "Concentration is really important for a goalkeeper and you have to be ready to make a save, even in the last minute. I was glad to be called on because it makes me feel part of the win."
Town ensured victory with goals in the seventh and eighth minutes, with Scott Arfield finishing from close range before Gary Roberts smashed home an angled drive, with Lee Novak the provider both times.
That should have been the signal for Town to crush their Blue Square South opponents – but that never happened.
The Town players relaxed too much and allowed Dover to rebuild their shattered confidence.
Roberts cleared off the line in the first half from Olly Schulz's powerful header before Arfield fired over and Pilkington saw an effort saved by Ross Flitney.
In the second half, Novak's delicate header was deflected wide and Roberts was denied by Flitney's out-stretched arm.
Kevin Kilbane hit a rasping shot only for Flitney to thwart him ahead of Smithies' late stops.
HUDDERSFIELD TOWN: Smithies, Peltier, Kay, P Clarke, Ridehalgh, Pilkington, Arfield (T Clarke 68), Kilbane, Roberts (Carey 73), Rhodes (Lee 59), Novak. Subs not used: Bennett, McCombe, Gudjonsson.
DOVER ATHLETIC: Flitney, Fish, Schulz, Gillman, Wynter, Baker, I'Anson, Cutler (Wallis 78), Cogan (Long 68), Hunt, Birchall. Subs not used: Hill, Briand, Reggett, Hook, Humphrey.
REFEREE: Tony Bates (Staffs).