Luke Gale’s 40m match-winning drop goal in the 74th minute proved the difference as they claimed a 31-24 victory, their first at KC Stadium since 2011. Denny Solomona also completed a hat-trick as Castleford came back from 24-22 down late on.
Powell said: “We needed a couple of players to step up in the second half and they did that
“Grant Millington got better, Nathan Massey came on and had a big influence in the middle and I thought Ben Crooks was excellent on his first game back here. Under the pressure he would have been under in his own mind, I thought it was a huge effort.
“Just for us to win the game in the way we did, though, at the end having had leads and lost them showed a fair bit of resilience. It’s a big win for us. A real big win for us.”
Powell added: “Galey was telling me this week he was rubbish at drop-goals.
“But that moment was massive for us.
“We can improve in all sorts of areas but this result makes us look a very good side.”
“Jy Hitchcox only knew he was playing 20 minutes before the game and was really good with some crisp finishes and he looked really sharp all night.”
Hull coach Lee Radford said: “Obviously I’m bitterly disappointed with the result but I’ve no qualms with losing to them tonight.
“It was a bit like the games against the NRL last week.
“We matched them physically but they were better on the ground and they burned us at the ruck.
“There was no composure in chasing the game but Jamie Shaul’s work off the ball was outstanding.
“The stinging he had from last year has obviously freshened his mind.”