Goals from Darren Ambrose, Patrick Kluivert and Shola Ameobi gave Newcastle a first Premiership win on their travels since November.
Ambrose pounced to score after James Milner had nodded down a Charles N'Zogbia cross from the left wing.
N'Zogbia set up Kluivert to head a second before Ameobi pounced from close range to secure the win.
Fulham grabbed a late consolation when Tomasz Radzinski finished well from Liam Rosenior's through-ball.
Newcastle started the game with Alan Shearer not even on the bench, manager Graeme Souness opting to rest the skipper.
But they were able to end their run of seven league games without a win mainly due to an abject defensive display by the Cottagers.
Chris Coleman's outfit looked like a side who had packed up for the summer, having already secured their Premiership safety.
They were the first to threaten when Mark Pembridge's free-kick just evaded the head of Zat Knight.
But despite Fulham enjoying the bulk of the possession Newcastle always looked the most dangerous.
Ambrose gave a warning of his ability to get forward when he broke through the centre and Rosenior did well to block his shot from the edge of the area.
On 18 minutes Ambrose was not to be denied a second goal in four games.
N'Zogbia found space down the left and crossed for Milner, whose knock down was blocked by Rosenior and Ambrose reacted quickly to direct his low shot past Edwin van der Sar.
Ten minutes later Kluivert almost profited from Milner, who twisted and turned Rosenior before crossing for the Dutchman to head over.
Fulham's best chance of the opening half came when Titus Bramble allowed former Magpie forward Andy Cole to spin and run on to a lofted pass.
Shay Given came off his line to beat Cole to the ball but it fell nicely to Lee Clark who headed over with an empty net in front of him.
Fulham continued to control the ball after the break but fell further behind to a rare Newcastle attack.
N'Zogbia again provided the ammunition, this time with a corner that an unmarked Kluivert squeezed past Pembridge at the near post.
Substitute Claus Jensen set up Luis Boa Morte - reportedly a one-time target of Newcastle - to shoot over from the left side of the penalty area.
But Newcastle made sure of the points when Ameobi was able to rise unopposed and head in an inswinging corner from Milner, with Van der Sar horribly exposed.
Radzinski gave the home fans something to cheer about when he calmly slotted past Given after Rosenior's perfectly-weighted pass had beaten Bramble.
Brian McBride could have made it an interesting final minute but his shot was well saved by Given.
Fulham: Van der Sar, Volz, Knight, Goma, Rosenior, Radzinski, Pembridge, Clark, Boa Morte, Cole (Jensen 66), McBride.
Subs Not Used: Bocanegra, Crossley, Rehman, Pearce.
Booked: Van der Sar.
Goals: Radzinski 86.
Newcastle: Given, Carr, Boumsong, Bramble, Taylor, Milner, N'Zogbia, Faye, Ambrose, Ameobi, Kluivert.
Subs Not Used: Andrew O'Brien, Harper, Robert, Brittain, Ramage.
Goals: Ambrose 18, Kluivert 62, Ameobi 75.
Ref: G Poll (Hertfordshire).