England hopeful Daryl Clark scored his first-ever hat-trick of tries as Castleford completed the double over Widnes in their dress rehearsal for next month's Tetley's Challenge Cup semi-final.
The Tigers' 40-20 win, which followed a 34-22 home win in May, confirmed their challenge for a first-ever top-four finish in the First Utility Super League and cast fresh doubt over the Vikings' play-off credentials after just one win in their last seven matches.
Widnes complained bitterly at referee Phil Bentham's decision to disallow a try by winger Patrick Ah Van on 56 minutes with their side only six points behind but the visitors were good value for their win, which was based on a blazing start in which they scored three tries in the first 10 minutes.
Clark was the big hero while skipper Michael Shenton grabbed two tries and stand-off Mark Sneyd dispelled any doubt over his commitment to the Tigers for the rest of the season with a polished performance in the week he announced a move to Hull for 2015.
Scrum-half Jamie Ellis, another player linked with a move away from Castleford at the end of the season, justified his recall at his selection ahead of Liam Finn when he offloaded from a tackle to get full-back Luke Dorn over for the first try after only two minutes.
Sneyd then got Shenton through a gap and second rower Oliver Holmes was in support to claim the Tigers' second try.
Widnes were still recovering from that early double blow when they allowed Castleford winger Kirk Dixon far too much space as he ran back a kick from his own line and Clark finished off the length-of-the-field break for his first try.
Sneyd converted all three to put his side into a commanding 18-0 lead before stand-off Kevin Brown sparked the Vikings' fightback with a long pass that got winger Paddy Flynn over at the corner on 14 minutes.
Danny Tickle added the touchline goal and, rejuvenated by the score, the home side launched a furious onslaught which Castleford did well to quell.
But for a series of handling errors, the Vikings might have been level but all they had to show for their efforts was a solo try from second rower Danny Galea, who beat three defenders on a determined run to the line.
Tickle's second goal cut the gap to six points but Widnes were undone once more before half-time by Sneyd, who re-gathered his own neat chip over the defence to send Shenton over.
Sneyd was off target for the first time with his conversion attempt and the gap was back down to six points on 50 minutes when Widnes full-back Rhys Hanbury broke from his own 20-metre area and fed Ah Van, who produced a devastating finish for his side's third try.
Ah Van thought he had scored again six minutes later when he intercepted Dorn's pass and went 80 metres upfield only for referee Bentham to disallow the try for offside on the advice of his touchjudge Robert Hicks.
It proved to be the Vikings' last chance as Castleford struck with two tries in five minutes to put the result beyond doubt.
Clark demonstrated lightning pace from dummy half to open up the Widnes defence and go on a mazy, 60-metre run for his second try while second rower Weller Hauraki pounced on the latest handling error by Galea to set up the position for Shenton to grab his second.
Clark then completed his hat-trick seven minutes from the end with another long-range opportunist score and Sneyd took his goal tally to six from seven attempts before centre Chris Dean scored a consolation try for the Vikings.