Goals from Mark Viduka and Michael Owen gave Newcastle their first win in 14 league games and boss Kevin Keegan's first in 10 matches since his return.
Viduka struck in the sixth minute when he collected a pass from Geremi and fired low past goalkeeper Kasey Keller.
Owen should have doubled their lead with a close-range header before nodding in from Geremi's free-kick.
Jimmy Bullard had Fulham's best chances but his long-range efforts were comfortably dealt with by Steve Harper.
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Victory will be a massive relief to Newcastle, who move six points clear of the relegation zone after their first win in the Premier League since a 1-0 win at Fulham on 15 December.
But the signs seem ominous for the west London outfit, who are now four points adrift of safety with seven games left.
The visiting team were gifted enough possession during the first half but time and time again failed to come up with the killer ball.
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Their downfall was self-inflicted at the other end of the field where Roy Hodgson's men produced a display that could politely be described as inept and in the sixth minute Viduka took advantage of that.
The Australian, who had not played for nine weeks prior to last week's draw at Birmingham, controlled Geremi's pass from the right, turned then drilled his shot into Keller's bottom right.
Owen, the hero at St Andrew's should have made it 2-0 but he could only head Geremi's clipped ball into the hands of Keller after finding himself inexplicably free eight yards out.
The England striker also had a 20-yard shot tipped over by the American shot-stopper, who then had to be alert to divert Obefemi Martins' low effort round the post.
Harper had his hands kept warm on a wintery Easter Saturday by the spirited Bullard, who fired in a couple of shots from distance that the Newcastle keeper had to crouch down low to save.
Keegan's men, who looked edgy in the first half despite taking an early lead, were far more confident after the break although shots on goal were few and far between.
They always looked potent though and Joey Barton, who along with Nicky Butt was one of the stars of the show, came closest to doubling his side's lead when he whacked a 20-yarder that missed Fulham's right-hand upright by a foot.
The result was still in doubt until the 83rd minute when Owen leapt above the Fulham defence to score his second in two games.
And with that, some of those growing concerns on Tyneside seemed to drift away.
Newcastle manager Kevin Keegan on Owen:
"Michael probably answered a few critics again today - there are plenty out there, from what I am seeing.
"He would certainly be in most people's England side."
Fulham boss Roy Hodgson:
"But having said that, seven matches, a lot of things can happen.
"We've got to keep believing that our football can get us out trouble and hope things start going right."
Newcastle: Harper, Beye (Edgar 87), Taylor, Faye, Jose Enrique, Geremi, Butt, Barton, Owen, Viduka (Smith 84), Martins (N'Zogbia 74).
Subs Not Used: Forster, Carroll.
Goals: Viduka 6, Owen 83.
Fulham: Keller, Stalteri (Healy 84), Hughes, Hangeland, Konchesky, Andreasen, Bullard, Murphy (Volz 71), Davies, McBride (Dempsey 66), Johnson.
Subs Not Used: Warner, Bocanegra.
Booked: Volz.
Att: 52,293
Ref: Alan Wiley (Staffordshire).
BBC Sport Player Rater man of the match: Newcastle's Mark Viduka 8.16 (on 90 minutes).
• Please note that you can still give the players marks out of 10 on BBC Sport's Player Rater after the match has finished.
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