Pirates led 1-0 at the break through Tendai Ndoro, but SuperSport blitzed them after the break as The Buccaneers slipped to their joint heaviest defeat ever, matching a loss by the same scoreline to Mamelodi Sundowns in the BP Top 8 in 1990.
Thuso Phala went close early on for the home side as his snap-shot zipped off the wet surfance and forced a fine save from Brighton Mhlongo in the Pirates goal.
SuperSport lost midfielder Cole Alexander to what appeared to be a hamstring injury on 19 minutes, replaced by Thabo Mnyamane.
The home side had a number of half-chances, but the best of the opportunities fell Pirates' way.
Mpho Makola wriggled into the box but delayed his shot twice and when he did eventually pull the trigger, Ronwen Williams had narrowed the angle and could make the save.
Thabo Rakhale then produced a brilliant defence-splitting pass with the outside of his boot, but an on-rushing Riyaad Norodien could only get the slightest of touches on the stretch and Williams was able to gather easily.
Tendai Ndoro went even closer when Williams rushed to the edge of his area to collect a deep cross, but was beaten to the ball by the Zimbabwean forward. His goal-bound header was cleared off the line by Morgan Gould though.
The pressure finally paid off though as Rakhale found space behind the SuperSport defence and his cross was bundled home by Ndoro for his seventh goal of the season.
But SuperSport were level seven minutes after the break when Reneilwe Letsholonyane powered an angled shot at goal and Mhlongo could only beat the ball into his own net.
Two quick goals from Michael Boxall then set SuperSport on their way to victory. The first turning home a shot from Letsholonane and the second a bubdled effort after Mhlongo could not clear with a punch.
Another error from Mhlongo deepened the misery for Pirates when his punch straight to Phala on the edge of the box allowed the winger to blast the ball home and make it 4-1 to SuperSport.
The fifth goal was coming and it duly arrived on 74 minutes when Bradley Grobler headed past the hapless Mhlongo to compile the misery for Pirates.
SuperSport got their sixth when Jeremy Brockie won a penalty after he was fouled by Mhlongo, though the contact was made outside of the penalty area. He converted easily from the spot.
Pirates had the opportunity to pull a goal back late on, but Ndoro saw his penalty saved by Williams to compund a miserable night for the Buccaneers.