Michael Shenton, Luke Dorn and Richard Owen each helped themselves to three tries as the engage Super League's bottom club produced a ruthless display to crush a patched-up Harlequins side 66-12 at the Stoop.
Quins, bereft of a host of regulars through injury and suspension, had no answer to Castleford's attacking performance as the visitors belied their lowly position to cross for 13 tries.
Tigers started as they meant to go on in the 10th minute minutes when winger Michael Wainwright broke down the touchline, and despite his offload going to ground, Stuart Donlan gathered to race over.
Quins struck back shortly after, Chris Melling crashing over after Henry Paul's pass took out three tacklers.
But the Tigers took control with a breathless 10-minute burst, taking advantage of some woeful home tackling to score three tries.
Firstly, after a Jon Grayshon fumble, Richard Owen shrugged off a poor Melling tackle to cross with ease.
Then, after Scott Moore was held just short, the ball was spun wide for Michael Shenton to slide over.
Finally, a neat inside pass from Brent Sherwin allowed Luke Dorn to breeze over unopposed.
Quins briefly threatened a revival when another excellent Paul pass saw Grayshon canter over.
But Castleford quickly wiped that score out when Shenton crossed again, Kirk Dixon adding his fourth conversion.
The visitors continued their dominance after the break, running in a further eight tries to secure their best victory of the season.
Moments after the restart, Ned Catic found a gap, produced a burst of speed and dummied Melling to scorch over.
Then Dorn showed a turn of pace to outrun the Quins defence and scamper over in the corner.
Worse was to follow for the hosts as Owen, Ryan McGoldrick and Shenton all crossed as the Tigers racked up a half-century.
But the visitors still were not finished, Owen bursting down the touchline to score in the corner, with Wainwright and Dorn following suit.