There were shades of Radford's last match in charge of the Black and Whites, a humiliating 38-4 defeat at the hands of Warrington Wolves in March 2020.
Hull simply imploded on Radford's first return to the MKM Stadium on their way to a sixth defeat in seven games, a run of form that has brought back memories of last year's collapse.
The Airlie Birds were 18-8 up after half an hour but Castleford ran in 38 unanswered points to claim a stunning win.
Leeds United ‘would have taken’ four points from two games according to Alan Shearer
Leeds United U21 2-2 Norwich City U21 highlights: Joseph and Perkins score again
Leeds United ‘have not’ approached pair but in transfer ‘talks’
Rodrigo makes 'sleeping' Leeds United admission and declares action plan after Whites punishment
Leeds United's new predicted Premier League finish after double boost with new lows for rivals
Derrell Olpherts - one of five players carded in an action-packed contest - helped himself to four tries and former Hull winger Bureta Faraimo crossed twice during a remarkable period with Jake Mamo in the sin bin.
It was a dream homecoming for two-time Challenge Cup winner Radford, whose ever-improving side move to within two points of fourth-placed Catalans Dragons.
By contrast, Hodgson is under increasing pressure after seeing Hull replaced in the top six by rivals Hull KR.
Not even Jake Connor could bring about a change in fortunes after falling flat on his return to the side.
It was an inauspicious start by Connor, the talented playmaker spilling the ball at the end of Hull's first set of the match.
Castleford came away with points the first time they entered FC territory thanks to the boot of Danny Richardson after the hosts were caught offside.
Radford vowed to send traffic in Connor's direction as he settled back in on Hull's right edge and the Castleford boss was as good as his word.
Connor failed to deal with a rampaging Kenny Edwards, giving the Tigers back-rower the chance to get a classy offload away.
There was still work to do but Greg Eden was up for the challenge, getting away a smart kick to give Olpherts an easy finish.
When Richardson stepped up to make it 8-0 inside nine minutes, there was a sense that Hull were in for another long night after shipping 150 points in their previous three games.
But the match swung dramatically in their favour for a period after both teams were reduced to 12 men.
Eden sparked a melee when he barged into Connor Wynne going for Connor's kick in behind, which the Hull centre took exception to.
Wynne engaged in some pushing and shoving after Olpherts waded in, an incident deemed worthy of 10 minutes in the sin bin for both players.
The scuffle awoke the Black and Whites from their slumber with Hodgson's side going on to score three quickfire tries.
Mitieli Vulikijapani got Hull going with a strong finish out wide after crisp ball movement and the Tigers suffered another blow when Gareth O'Brien was forced off with a head injury that ruled him out of the rest of the game.
Luke Gale's 40/20 took the Airlie Birds back into Castleford territory and they left with points again, Darnell McIntosh touching down Connor's kick millimetres from the dead-ball line.
Gale nailed his second touchline conversion to maintain Hull's momentum before quick thinking from Danny Houghton put the home side in control.
The Tigers switched off after conceding a penalty near the halfway line and Houghton took advantage by racing clear to score under the posts.
Olpherts - together with Wynne - had returned from the sin bin in time to see Houghton coast over and the Castleford winger quickly atoned for his lapse in discipline, powering his way over out wide in heavy traffic.
Richardson reduced the deficit to 18-14 with another fine conversion and that is how it remained as referee Chris Kendall brought a breathless first half to an end.
Castleford were dealt another injury blow when Alex Mellor failed to return to the field and found themselves down to 12 men once again after Mamo was yellow-carded for dissent.
But they defied their one-man disadvantage to stun the home crowd with a quick one-two through Faraimo.
First the winger picked off Connor's pass to go 90 metres before finishing in the corner two minutes later on the back of a slaloming run by Olpherts.
Castleford were not done there, making it three tries with 12 men when Suaia Matagi coasted over from Dan Smith's pass.
Matagi's try sparked a chorus of boos from the shell-shocked home supporters and the Tigers were in the mood to pile on the misery.
After Connor was forced into an error by Mahe Fonua, Castleford quickly turned defence into attack with Eden putting Olpherts over for his hat-trick.
Wynne was sin-binned for a second time after showing his frustration in the aftermath of Olpherts' try and it got even worse for the hosts when Ligi Sao was sent off for a swinging arm on Mamo.
Connor followed Sao off the field and Olpherts helped himself to a fourth with a flying finish in the corner.
Alex Sutcliffe rounded off a miserable evening for Hull when he picked off Scott Taylor's pass to race over, although Castleford ended the game with 12 men after George Lawler was sin-binned in the dying seconds.
Hull FC: Walker, McIntosh, Wynne, Vulikijapani, Simm, Connor, Gale, Sao, Houghton, Evans, Lane, Lovodua, Fash.
Substitutes: Brown, Johnstone, Taylor, Longstaff.
Castleford Tigers: Eden, Faraimo, Sutcliffe, Fonua, Olpherts, O'Brien, Richardson, Griffin, McShane, Lawler, Edwards, Mellor, Westerman.
Substitutes: Mamo, Milner, Smith, Matagi.