First-half headers from Wells and Filip Benkovic plus a 58th-minute volley from Famara Diedhiou had the hosts 3-0 up before a diving header from Martyn Waghorn and a Chris Martin tap-in sparked a frantic finale.

A delighted Johnson said: "Goalscorers win you games and we have brought Nahki Wells in to do just that.

"I have had some really good strikers here during my time in charge, but in terms of cold, calculating finishing he is the best.

"You can see that by watching him work on the training ground. His goal tonight has changed the game and hopefully there will be a lot more to come.

"It wouldn't be us if we didn't give our fans a scare. But you have to put in a huge amount of effort to be three up on a team as good as Derby.

"We were bound to flag at some stage. Korey Smith felt a nick in his knee and had to come off when we didn't have a like-for-like replacement on the bench.

"I think we could have managed the game better in the closing stages, but overall I am delighted with the result and the way our supporters stuck with the team when we were under pressure at the end."

Derby boss Phillip Cocu admitted to being angered by the outcome.

"We controlled the game for long periods and lost because of set-pieces," he said.

"We have to be better at marking and stopping crosses. We are scoring more away from home, so it is very frustrating to lose to goals like we conceded tonight.

"I thought in every other respect we played a very good game. To come back from three goals down is never easy, but we almost did it.

"The players were sure we should have had a penalty for handball in the second half, but it was difficult to see from my position. And why there were only four minutes of stoppage time I can't imagine.

"The result will not affect confidence because we have been on a good run and produced another very good performance.

"But defending set-pieces is something we have to work on if we are to get the points we deserve.

"Bristol are very good at getting crosses into the box, but we have to be stronger."