While some feared the Cottagers may struggle with a hangover from their midweek European exertions, they dominated from the offset against their neighbours from less than three miles up the road.
Andrew Johnson was the standout performer for the Whites, netting a hat-trick as Fulham secured their first Premier League victory of the season.
Hangeland admitted the start of the season has been frustrating for everybody involved with the club, although he believes Sunday's result can act as a catalyst.
"It was a great, great day at work finally after a few disappointments and quite a slow start to the season," he said.
"We've tried to get goals and then all of a sudden they come at once so it was a good result for us.
"There is a bit of pressure off us and we can prepare well for the next game.
"We're always under pressure but especially when results have not been as good as they should be.
"We're very happy to get that result against QPR."
Fulham impressed as a cohesive team unit throughout the 6-0 win despite reports emanating earlier in the day about divisions within the camp.
There had also been talk that manager Martin Jol's position was coming under threat but Hangeland rubbished such suggestions.
"We're all in this together and everyone involved with the club can feel a bit of extra pressure when things haven't gone as well as we wanted them to," he said.
"That goes for me, the rest of the players and I am sure the manager as well.
"We're very much a united club.
"I think there is always a bit of frustration when we play reasonably well and don't get the results and people wonder why this is happening.
"You can see we are still a good team and can take a lot of confidence form this."
He added: "The big thing for me is to score first in the Premier League.
"That gives us a little bit of a chance to relax and the other team has to chase it.
"We're quite good when we can sit back and counter-attack it, especially at home.
"To get that first goal finally after six games was a good feeling."
Having succumbed to a 6-0 mauling at Craven Cottage, the only positive for QPR was the return of striker Jamie Mackie after a long injury layoff.
The 26-year-old suffered a double leg break in an FA Cup tie with Blackburn in January and came on for his first appearance since then on Sunday.
"I am massively relieved to be back," he told Press Association Sport. "I've worked so hard for nine months and I have just been in the gym, grinding it out.
"I've been watching a lot of football and, while I like it, I would much prefer to be playing.
"I am delighted to be back now and hopefully I can make an impact for the manager and the lads.
"It was really hard but I am not the first one who has been injured for a long time.
"A lot of lads have had that in their career and it is part of the territory.
"You have to be strong and fortunately I am mentally strong anyway and I've got through it.
"If in doubt, I've just been thinking about getting back and luckily enough I am allowed to do that in the Premier League."