Trin were in control for the majority of the gripping Round 5 contest, leading 8-6 going into the final quarter before two quick tries from Ed Chamberlain and Lewis Martin put the Black and Whites in front for the first time.
And Hull FC held on despite a late consolation try from Cameron Scott.
A frustrated Powell said after the 12-16 defeat:
“Really disappointed as we started so well. I thought we hurt ourselves way too much. We handed them way too much. We were unlucky in quite a few instances but we made too many errors and we feel like we’ve handed the game away.
“We’re talking about learning and making sure that we don’t hurt ourselves as much as we did tonight. It was pretty close.
“We definitely feel like it is a game we have given away and given way too many opportunities to the opposition.
“We could have easily won that game tonight.”
It could have been a different story had Wakey had at least one of three tries from Josh Rourke, Tom Johnstone and Mason Lino not been ruled out by the video ref.
“There’s not a lot you can do about it,” admitted Powell. “They all went against us tonight but I’m not complaining. We’ve done too much to ourselves. There are no complaints.
“We can’t do that much wrong and expect we’re going to win a game. The boys feel the same. The key thing for us is we don’t do that again.
“We have got a big couple of weeks coming up so we are going to need to unravel this quickly and make sure we learn some key lessons moving forward.”
He added: “The first one you can see he is offside but it is an unbelievable piece of skill and Josh Rourke does exceptionally well. But it’s just offside isn’t it?
“We were 8-6 for a long time, if we score one of them I’m not sure how the game goes then. They were clinging on for dear life at the start.
“I thought we started like a house on fire. We were really, really good.”
Scott’s try came on his first start for Wakefield, against his former club. But Jake Trueman was denied the chance to play against his ex-employers due to injury.
Powell said: “He had a little bit of a back issue, so we decided we’d leave him out.
“Oli Russell got an opportunity and he played really well.”
Take a look at these photos by Alex Whitehead/SWpix.com of Wakefield’s Round 5 clash with Hull FC.

1. Wakefield Trinity v Hull FC
The teams line up before kick off. Photo: Alex Whitehead/SWpix.com

2. Wakefield Trinity v Hull FC
Caleb Hamlin-Uele in action for Trin. Photo: Alex Whitehead/SWpix.com

3. Wakefield Trinity v Hull FC
Aidan Sezer is tackled by Caleb Hamlin-Uele and Mike McMeeken. Photo: Alex Whitehead/SWpix.com

4. Wakefield Trinity v Hull FC
Tom Johnstone is tackled by Zak Hardaker and John Asiata. Photo: Alex Whitehead/SWpix.com