Hull deserved their victory, despite a gutsy effort from patched-up Tigers, but it wasn’t all good news for the hosts who lost scrum-half Marc Sneyd to a leg injury early in the second half.
They were already without stand-off Albert Kelly, whose new two-year contract was announced before the game.
Sneyd’s injury disrupted the home side and Tigers, who looked in danger of a heavy defeat at the break, hung in gamely for most of the second period before Hull staged a strong finish.
Their Man of Steel Luke Gale was beginning an expected three-month layoff with a fractured kneecap and Ben Roberts, Greg Eden, Jake Webster, Nathan Massey and James Clare were also ruled out.
Tigers fielded forwards Joe Wardle and Alex Foster in the centres and captain Michael Shenton moved to the wing. When Jake Trueman was hurt midway through the first half Shenton switched further out of position to full-back.
Jake Connor’s drop-off pass created the first of Sika Manu’s brace of tries to nose the hosts ahead after 13 minutes, Sneyd converting, but Tigers were level almost immediately.
Jamie Ellis’ high kick was taken brilliantly by Michael Shenton who lobbed a pass infield to send the makeshift half-back Paul McShane over.
Ellis added the extras, but Hull dominated the rest of the half to take a 20-6 interval lead which Tigers never threatened to overturn.
There was a suspicion of obstruction when Jamie Shaul weaved over for an unconverted try on 19 minutes and nine later Sneyd’s kick to the corner was dropped by Calum Turner, the youngster who had just come on for his Castleford debut and Manu was gifted a walk-in.
Sneyd tagged on the two and three minutes later his kick was knocked back by Connor to Josh Griffin and he sent Bureta Faraimo over.
Wardle was penalised for interference on Connor at the start of the second half and the stand-off got up to take the two points with a long-range kick, Sneyd having been hurt moments earlier.
Castleford refused to throw in the towel and Turner gave them hope with a debut try on 50 minutes, moments after Manu had been held up over the line by McShane as he tried to snatch a hat-trick score.
Shaul could not take Ellis’ high kick and Turner was on the spot to gather and race over, giving Ellis a straight-forward conversion. The youngster was denied a second try by a touch judge’s flag, for a foot in touch, with 17 minutes left.
A touchdown then would have set Hull’s nerves jangling, but they counter-attacked and Faraimo went over for his second try, from Griffin’s pass soon afterwards and Conor landed a magnificent goal from the touchline.
Connor kicked a penalty on 74 minutes and converted after Faraimo’s break was finished off by Griffin three minutes later.
Tigers dropped to fifth in the table, with Leeds Rhinos slipping a place to sixth.