The England winger scored two fine goals before dispatching a late penalty as Gus Poyet's men took a huge step in the fight against relegation at the expense of the Cottagers.
After coming off the bench to devastating effect in Sunderland's Capital One Cup semifinal first-leg win over Manchester United in midweek, Johnson made his first league start since early December and he produced a match-winning display.
He gave the Black Cats the lead when he expertly converted a free kick on the half hour before he was involved again just before halftime as he assisted Ki Sung-Yueng in scoring Sunderland's second.
The home side was resurgent at the start of the second period and quickly pulled one back through Steve Sidwell but Johnson grabbed his second of the match with 21 minutes left to effectively wrap up the three points.
|VIEW FROM CRAVEN COTTAGE
|By Jay Jaffa
Well, I said from the start that I felt the key battle would be John Arne Riise up against Adam Johnson and it proved to be correct as the Sunderland wideman tore Fulham to shreds through a combination of quality set pieces and precise finishing.
He was helped by Ki Sung-Yeung, who played intelligently throughout - it is still a mystery why Swansea let the South Korean depart on loan this season.
Gus Poyet is the beneficiary of such generosity and he may want to give Rene Meulensteen a cheeky pat on the back for the charitable defending that the Cottagers afforded Sunderland. Riise was terrible, David Stockdale woeful and the rest of the defense not much better. If Fulham is to survive this season the club will have to invest in a center back and left back this January.
As for Poyet's side, he has it moving in the right direction. There was an aura of confidence to the team's play and this excellent result lifts it off the foot of the Premier League for the first time since November.
Fulham boss Rene Meulensteen made eight changes from the FA Cup draw at Norwich City - Clint Dempsey one of just three players to keep their place as he made his return to Premier League football. As well as Johnson, meanwhile, Jack Colback also returned as Gus Poyet's only other alteration.
After a quiet opening 20 minutes, both sides went close as Steven Fletcher headed just over the crossbar following a well-worked free kick for Sunderland, while the tricky Adel Taarabt forced Vito Mannone into a reflex save from a narrow angle.
The deadlock was finally broken just before the half-hour mark, however. Johnson won himself a free kick just outside the Fulham area and the winger curled it into the top corner, despite David Stockdale getting both hands to the ball.
Things got even worse for Fulham four minutes before the break. Johnson cut a free kick back towards the penalty spot and Ki's low, first-time strike found the back of the net via a deflection off Philippe Senderos.
Fulham was gifted a lifeline seven minutes into the second half when Damien Duff's inswinging corner found its way through to the unmarked Sidwell, who glanced a header home.
The home side's need to attack saw the match become increasingly stretched from there and Sunderland almost capitalized when Fabio Borini hit a drive wide from the edge of the area, before Stockdale clawed Lee Cattermole's 30-yard effort away.
With Fulham throwing players forward, the visiting team produced a decisive counterattack to restore its two-goal lead in the 69th minute. Ki combined with substitute Altidore before slipping a delicate through ball into the area for Johnson, who slotted past Stockdale with ease.
Altidore played an important role again late on as he won a penalty against Senderos and Johnson confidently scored to complete his hat trick.