Harry Redknapp suffered his first defeat as Tottenham boss as Fulham sent them back into the relegation zone.
Former Spurs winger Simon Davies was credited with the first goal, though it was another awful error by Heurelho Gomes, who fumbled into his own net.
With the visitors in disarray from corners, Andy Johnson pounced to turn in the second inside the six-yard box.
On 81 minutes Spurs substitute Fraizer Campbell slotted home to create late tension but Fulham deserved their win.
Redknapp had presided over three victories and a thrilling 4-4 draw at Arsenal since moving to White Hart Lane from Portsmouth but his team produced by far the most ineffective display of his tenure.
Fulham enjoyed the better early as Danny Murphy had a shot from the edge of the box blocked by Vedran Corluka and Johnson blazed over from 12 yards.
Gomes showed the more positive side of his game with a stunning one-handed diving save to keep out Clint Dempsey's long-range, left-foot drive.
But it will again be his errant handling that will be scrutinised after a cross-shot from Davies, which flicked off Jonathan Woodgate's head, somehow squeezed through the keeper's hands.
Spurs looked comfortable in possession but struggled to supply lone striker Darren Bent with sufficient ammunition.
Luka Modric, so influential in recent matches under Redknapp had one weaving run but his shot was way off target.
David Bentley then fired a low 20-yard volley inches wide, while Bent volleyed tamely at Mark Schwarzer having squeezed between the two central defenders to reach Tom Huddlestone's raking pass.
Modric and Huddlestone were sacrificed at half-time in favour of Aaron Lennon and Roman Pavlyuchenko as Spurs switched to a 4-4-2 but Fulham remained largely in control.
They threatened the increasingly anxious Spurs defence with every set-piece, and the second goal arrived when a loose ball was not cleared and Johnson was the fastest to react, spinning on the edge of the six-yard box to poach his fourth league goal of the season.
Gomes pushed away a thunderous 25-yard free-kick through a crowd of players from Jimmy Bullard and held on to a low Davies drive from similar range.
Still the shots came flooding in, Bullard with another long-range effort that Gomes - more at home with the spectacular - kept out superbly.
Spurs were given a lifeline when Jermaine Jenas produced a surging run, found Bentley and his pass teed-up Campbell, who calmly slotted in first time with his right foot from an acute angle on the edge of the area.
Redknapp's team pressed forward in numbers, but for the first time in his Tottenham reign, he was unable to inspire a magical comeback as Fulham secured their fifth home win of the season to move up to ninth.
Fulham boss Roy Hodgson: "It was one of best performances of the season, the way we set about them going forward.
"Our front two were up against two quality centre-halves but I thought we caused them problems throughout.
"But over the 90 minutes, the way we played and the amount of pressure we put on the Spurs defence, I don't think we've got any reason to do other than pat ourselves on the back and to claim the victory."
Tottenham manager Harry Redknapp: "We started in second gear and suddenly looked like we were getting into the game until we gifted them a goal.
"It was a farcical goal, but he's my goalkeeper. He's got to do the job. This is the situation I have.
"Gomes is the first-team goalkeeper. His record at PSV Eindhoven tells you he was a world-class goalkeeper. He made some great saves after the goal, so I have got to keep believing in him and stay with him.
"The goalkeeping coach has got to work with him. I always think goalkeepers and their coaches have a special relationship and he's got to get into his head this week."
