Gareth Hock grabbed four touchdowns for Widnes who tossed away victory by conceding three late tries to Castleford.
Rangi Chase was in commanding form and his teasing kick led to Justin Carney’s opening try after eight minutes, but too far out for Dixon to convert against a strong wind.
A surging break from skipper Kevin Brown lifted Widnes, with Jon Clarke’s short pass from dummy-half sending Hock over but Patrick Ah Van missed the straightforward conversion.
But Cas regained the lead after 17 minutes with Chase feeding Milner for Ryan Boyle to crash over, with Dixon’s goal making it 10-4.
Hock was involved in a couple of skirmishes before the Vikings fell further behind, with Chase again the instigator for Michael Shenton’s looping pass to send Carney over in the corner.
It got even worse for Widnes after 27 minutes when Isa failed to collect Chase’s kick and substitute Nathan Massey accepted the gift to stroll over, with Dixon’s conversion stretching the lead to 20-4. The Vikings did manage to cut the gap with Joe Mellor picking up a loose ball to dart 70 metres and cross for his 11th try of the season, but Ah Van again missed the easy goal attempt.
Cas were in a hungry mood with Jamie Ellis scampering over to extend the lead to 24-8 before the Vikings fought back.
Hock showed his class for Widnes after being put through a gap by brother-in-law Brown and then taking a return pass from Rhys Hanbury to notch his second try. Stefan Marsh took over the goal-kicking and was on target to make it 24-14.
There was no stopping Hock, who took Hep Cahill’s pass to complete his hat-trick and cut the arrears to 24-18 at the break.
Daryl Clark limped off for Cas early in the second half before a high tackle by Craig Huby put the Tigers under pressure, and it proved costly with Clarke sending Hanbury over and Marsh’s conversion levelling the scores.
The Vikings went in front for the first time with a Winterstein try and Owens adding the extras. Widnes had their tails up with Hock notching his fourth try from another Clarke pass on the hour to make it 34-24.
Chase and Brown were involved in a flare-up 15 minutes from time with referee Richard Silverwood correctly sin-binning both players. Milner scrambled over for the Tigers’ sixth try after 68 minutes with Dixon’s conversion cutting the gap to 34-30.
Hauraki levelled the scoresand Cas wrapped up a dramatic victory with Channing taking Richard Owen’s pass to cross, with Dixon again on target for the extras. Winterstein notched his second try for Widnes in the last minute but it was too late.
Widnes: Hanbury, Isa, Marsh, Phelps, Ah Van, K Brown, Mellor, O’Carroll, Clarke, Kavanagh, Hock, Leuluai, Cahill. Subs: Gore, Joseph, Winterstein, Owens.
Castleford: Owen, Dixon, Shenton, Channing, Carney, Chase, Ellis, Boyle, Milner, Huby, Millington, Hauraki, Clark. Subs: Massey, Thompson, Fleming, Martin.
Referee: Richard Silverwood (Mirfield).