Hull's 20-year-old centre Ben Crooks scored four tries but still ended up on the losing side, as Powell's men overturned a 16-6 half-time deficit with a purple patch that brought them three tries in six minutes. Even then, the visitors hit back to draw level and the decisive moment came when Tigers winger James Clare snapped up a loose ball and sprinted 95 metres for the all-important try.
"It was unbelievable to be honest," Powell said. "You didn't know which way it was going to go from start to finish."
He added: "I'm delighted for the team and delighted for the fans. It was good to see them at home at last. I'm obviously pleased to come out as winners but there are certainly some things we need to look at that we need to improve."
Rangi Chase helped create Castleford's only first-half try for Richard Owen and he sparked their second-half fightback with a sparkling touchdown.
"Rangi really got a grip on the game and everybody went with him," Powell said.
"I thought our pack was immense, especially Craig Huby and Grant Millington, but it was a team effort. We responded superbly. We were down by 10 points at half-time but there was nothing in it.
"In the first half we were under so much pressure. We had little ball and hardly any territory, but when we got it in the second half, we scored some quality tries and put them under enormous pressure."
Hull actually outscored their hosts by six tries to five but Daniel Holdsworth missed four conversion attempts, whereas Castleford's Kirk Dixon enjoyed a 100 per cent success rate with the boot. The Black and Whites almost snatched the win when Tom Lineham was held inches short of the line in the last few seconds, but coach Peter Gentle had no complaints over a second consecutive defeat.
"I am disappointed," Gentle said. "We didn't give ourselves a chance. We didn't deserve to win the game, we didn't deserve to be that close. We are a mile from where we were a month ago. We lacked a bit of composure and defending the way we are puts pressure on you. We have a lot of work to do defensively."
- Sports & Recreation