Jonas Gutierrez's header had given Newcastle a half-time lead, but Chelsea hit back to go in front through two excellent finishes from Frank Lampard and Juan Mata.
However, Chelsea's recent fallibility when in front came back to haunt them again as Sissoko equalised midway through the second half before the January signing drilled home from the edge of the box to give Newcastle back-to-back wins.
Newcastle made the brighter start at St James' Park, with new signing Yoan Gouffran combining well with Davide Santon down the left in the early minutes. The former saw the first shot in the opening 60 seconds but his tame effort barely troubled goalkeeper Petr Cech.
Sissoko hinted at the afternoon he was about to have when he set up Papiss Cisse for a shot but John Terry was there with the crucial block. Seconds later, Gouffran fed Santon, who cut inside to prompt a comfortable low save from Cech.
Chelsea also saw chances, notably when Lampard blasted high over from Ashley Cole's 15th-minute pull-back, but suffered a blow when Demba Ba, on his return to St James' Park after his move to Stamford Bridge, took a boot to the face from Fabricio Coloccini after bravely heading his rebounded shot wide and had to retire for treatment.
Ba returned to the pitch with his face heavily bandaged just in time to see Newcastle make their breakthrough. After Cisse had seen a long-range shot kept out by a fine Cech save minutes earlier, Gutierrez came again, meeting Santon's cross into the box with a glancing header to flick into the far corner. There was more woe for Chelsea just before the break as the injured Ba went off, with Rafa Benitez forced to introduce Fernando Torres.
A rip-roaring second half saw Chelsea back on level ground within 10 minutes as the influential Lampard struck from distance, chesting down Ashley Cole's ball before producing a sweetly-struck dipping effort that was typical of the England midfielder and left Krul with no chance.
Then, six minutes later, the Blues had gone ahead thanks to a superb Mata effort. The Spaniard, teed up by Torres on the right of the box, unleashed a delicious curling shot which landed decisively in the far corner.
Tensions were running high as Cisse and Ashley Cole both went into referee Howard Webb's book soon after that strike after clashing in the midst of the Blues' celebrations.
The goals continued to flow but it was Newcastle that next saw joy in the 67th minute, with Cech parrying Gouffran's shot from close range away but only as far as the outstanding Sissoko, who made no mistake in driving home a powerful drive for his first of the afternoon.
Sissoko then left it late to crown a dominant afternoon, starting a move by picking out Santon on the left before picking the ball back up and unleashing a stunning finish past Cech from the edge of the box to send the St James' Park crowd wild.
|Newcastle United||Team Statistics||Chelsea|
|1||1st Half Goals||0|
|11||Shots on Target||5|
|6||Shots off Target||7|
|50.6||1st Half Poss.||49.4|
|38.7||2nd Half Poss.||61.3|