Shaun Miller's last-gasp header secured the team 23rd in League One a 1-0 extra-time victory in Tuesday's fourth-round replay, as the west Londoners went the same way as Aston Villa in the previous round.
The Premier League scalps have been a welcome distraction for relegation-threatened United and Clough hopes the victory at Craven Cottage will boost his ailing side.
"The determination and resolve lacking on Saturday (in the 3-0 defeat to Crewe) we showed in abundance this evening," the former Derby boss said.
"We frustrated Fulham but I thought we were enough of a threat ourselves throughout the course of the game, especially the second half of normal time.
"It is important that we do take something from it and try and get back on track in the league.
"Some of the performances have been good but we haven't quite had our rewards
We sit second from bottom and have 19 games to get out.
"This is all very well winning at a Premier League side, but the priority remains staying in our league."
United return to League One action when Shrewsbury visit Bramall Lane this weekend and also face a home clash against Brentford before their fifth-round tie.
The opponents of that match will be decided on Wednesday night at Deepdale when Preston take on Nottingham Forest, with whom Clough played in the 1991 FA Cup final.
"At this moment, honestly, all we are doing is looking at Shrewsbury on Saturday," the United boss said.
"That will take care of itself in a couple of weeks' time
Just Shrewsbury on Saturday is all that concerns us and getting the players right physically after tonight's efforts."
Fulham, meanwhile, have to regroup to take on Manchester United at Old Trafford after a performance Meulensteen admitted was the worst since he succeeded Martin Jol at the helm.
Not only that, bookmakers have shortened odds on the Dutchman becoming the next manager out of a job, with the defeat to the Blades coming fresh on the back of reports that technical director Alan Curbishley could be drafted in as his replacement.
"Listen, (the owner's confidence) will only last until that is gone," Meulensteen said.
"Until that time, I will just jeep doing the job the best I can
I have no worries in that respect at all."
Source : PA
Source: PA