The Black and Whites have advanced to the quarter final stages after overcoming Castleford at Saints’ Totally Wicked Stadium.
Hull will now have six days rest before challenging Wigan next Saturday.
Castleford had two important changes as Cheyse Blair returned and Sosaia Feki, an off-season signing from Cronulla, finally made his debut.
Hull made eight changes from Thursday’s squad, with Ratu Naulago, Gareth Ellis and Jamie Shaul all notable inclusions.
Hull broke the deadlock first; Shaul’s break was followed up by Carlos Tuimavave under the sticks.
George Griffin replied for the Fords as he received a crash ball and pivoted his way over.
Albert Kelly strolled over and Tuimavave raced away for his second to provide Hull with a considerable 6-18 lead. Naulago extended this further after the interval with an interception score against the grain.
However, Castleford hit back with two scores as Oliver Holmes crossed from close range and Peter Mata’utia found space to go over.
Jake Connor converted two penalty goals and a drop-goal in the closing moments to alleviate any potential comeback from Castleford.
Castleford: Clare, Olpherts, Blair, Shenton, Feki, Mata’utia, Richardson, Watts, McShane, Griffin, Holmes, McMeeken, O’Neill; Subs: Millington, Milner, Hepi, Turner
Hull FC: Shaul, Naulago, Tuimavave, Griffin, Faraimo, Kelly, Connor, Ellis, Johnstone, Fash, Lane, Ma’u, Cator; Subs: Fonua, Houghton, Satae, Sao
A full match report from this game will be available in Monday’s League Express.