And despite both Tom Barkhuizen and Ben Davies hitting the woodwork, North End failed to find the net and saw their three-game winning streak come to an end.

"First and foremost my thoughts are that we should have won the game," Neil said.

"We've hit the woodwork twice and created more than enough chances, but we've lost the game to a really dubious penalty.

"I've seen them penalties given before, but was that a clear penalty decision? I wouldn't have said so.

"I don't think Darnell has deliberately tried to block the shot with his hand or his arm.

"Then there's the kick itself – Grabban has clearly taken two touches. He's gone for it with his right foot, then he's hit it again as he has gone down.

"It's really disappointing, and the second bit is unforgivable. You can tell by the players' reactions, especially Declan Rudd's.

"I've got a lot of respect for this referee, but I think he knows he's made an error today.

"That has been the single thing that has cost us. I really don't understand how you can't see a double touch in a situation like that."

The win for Forest extended their unbeaten run to five Championship matches, with Chris Hughton's side climbing out of the drop zone after starting the day in the bottom three.

And after taking nine points from a possible 15, the visitors look to be gaining momentum heading into the new year, with the win at Deepdale their first away from home since mid-October.

And Hughton did not need telling how important the victory was for his side, who climbed above rivals Derby to leave the Rams in the relegation zone.

"It feels like a really big win for us," the Forest boss said.

"I'm really pleased for a couple of reasons. Firstly, of course, it's come away from home, and secondly because it's helped our position in the league.

"That's not a comfortable position, and one we still need to improve greatly.

"The first-half performance was good. The frustration was that you need some value in those situations, certainly in terms of getting yourselves a goal or a lead when you're in that position.

"You do need that bit of luck sometimes, and they hit the crossbar in the second half, but we've deserved that result.

"Overall, though, over the 90 minutes I think we've gained a well-deserved win."

On the controversial penalty, Hughton believed Grabban's strike was not on the wrong side of the law.

He said: "At the time I couldn't really see. It was definitely a penalty, but the kick itself, I've since been told Lewis did slip, but it wasn't two touches. He kicked himself.

"It came at a big time for us, and I'm pleased because in some games this season we've not got what we deserved.

"Sometimes things do go your way, and undoubtedly today has been our day."