Tom Cairney marked his return after a 10-month absence with the goal that set Fulham on course for a 2-0 home win against Cardiff that increased the pressure on manager Mick McCarthy.
Cairney was introduced as a half-time substitute for his first appearance since December and he took just 12 minutes to fire the Cottagers in front.
Aleksandar Mitrovic added the second in the 63rd minute - his 13th league goal of the season - as Marco Silva's side moved up to second in the Championship.
For McCarthy, defeat means his struggling side have now lost their last seven league games, scoring just one goal in the process.
After such a dismal run of form, a trip to face a Fulham side buoyed by Saturday's comfortable 4-1 victory over QPR was hardly the fixture McCarthy would have chosen.
The Cardiff boss made five changes to the side that suffered a heavy defeat to rivals Swansea on Sunday.
But the ease with which Fulham forced a corner in the opening minute suggested this would be another testing 90 minutes for the Bluebirds.
It was the visitors who came closest to breaking the deadlock, though, when Kieffer Moore latched onto a bouncing ball on the edge of the box and fired a seventh-minute shot against the angle of crossbar and post.
Fulham responded to that warning with a well-worked move that was started by Tosin Adarabioyo's through ball and ended with Neekens Kebano directing a shot against a post.
Silva's side controlled long periods of the game but failed to make the most of their first-half dominance.
Bobby Decordova-Reid saw a shot blocked when Mitrovic was better placed and Kebano wasted a good free-kick opportunity by firing into the defensive wall.
Cardiff midfielder Marlon Pack had followed Moore's example in threatening the Fulham goal early on but the visitors were forced to concentrate their efforts on keeping the Cottagers at bay as the game wore on.
Fulham were still lacking a cutting edge, however, until Cairney appeared as a replacement for Harrison Reed.
The midfielder made his presence felt in spectacular style when he met an attempted clearance on the full with a left-foot shot that flew past Alex Smithies.
Having made the breakthrough it was always likely that Fulham would quickly add a second.
And it came just six minutes later when Decordova-Reid caught out Cardiff left-back Joel Bagan and squared for Mitrovic who made no mistake with a first-time shot from 16 yards.
What the managers said...
Fulham's Marco Silva: "It was really important for Tom to come back with the goal, it was really important. And he deserves it after the last few months that have been so tough. It was important for him to get back. You can imagine how he was. It is easy to understand how he celebrated the goal, his feelings in that moment.
"He helped the team when we needed him. I felt the team needed a player with more calm, to move the ball differently and be creative. If he is not the happiest, he is one of the happiest players in our dressing room. We can take many positives from the game. We deserved the three points and the clean sheet is really important as well."
Cardiff's Mick McCarthy: "This leaves us on the back end of a really horrible run of results. And if football is true to its usual stuff, we know what happens. I can't do anything about that. We've certainly had a much better performance, and I'll be doing exactly the same for Middlesbrough unless I'm told different. I can't do any more than I am doing, I can't try any harder than I am doing.
"It was a vast improvement as a performance. The players were happier, as I was. If we perform like that against other teams we will get results. I have no qualms with the players, in terms of the effort and the performance. But we should be better on the ball. I have no criticism of them at all in terms of performance. But you can keep saying that but you've got to stop losing games.
"I was asked at the weekend if I had lost the dressing room, which is ridiculous. Tonight shows that I certainly haven't. But I feel pretty lousy because I don't like getting beaten."