Two goals either side of half-time from Mirco Antenucci saw United hand a massive reality check to leaders Derby, who suffered their first defeat to Leeds in 13 matches in a 2-0 reverse.
It was a polished all-round display from Leeds, who produced the perfect response following last weekend’s shattering loss at Blackburn Rovers.
Redfearn said: “I thought we were excellent, they are a top side, you can see that.
“They caused us problems and it was a great game with two sides trying to play football. The finishing was out of the top drawer.
“To me this is part of the progression. I think we have been playing well and have played well in games and not got what we’ve deserved.
“Today we did and the more we put these performances in the better we will get.”
Aside from two-goal Antenucci, Redfearn had praise for teenage midfielders Lewis Cook and Alex Mowatt, who orchestrated the Leeds aggressive display that drew praise from Rams chief Steve McLaren.
“They are getting better and better, getting more experience and getting their feet under the table,” Redfearn said.
“We came on to them and it shocked them. They played well but we were better.”
McClaren was left to reflect on a “bad day at the office” for his Derby side, with the Rams suffering their first defeat to Leeds since September 2005.
While Derby remained top, they could have been four points clear, and McClaren was frustrated his men could not put some distance between themselves and the chasing pack in a game they were expected to win.
“We want to get out of the craziness, but we keep joining in,” he said of the Championship table.
“After 20 minutes, Leeds realised they had to do something as we were controlling the game. We joined in, but credit to Leeds if that was the game plan.
“It’s just one of them days, a bad day at the office. We were below our best and when you’re not (at your best), you can be beaten.
“In Antenucci, Leeds had someone who did what we couldn’t.
“On another day we could have scored three or four, but we could have been here until midnight and not scored.”
According to the former England manager, there was no suggestion of his side having taken Leeds lightly.
“I said before the game that if we were below our best this team could hurt us,” he added.
“Leeds knew they had to get about us, they frustrated us and we lost our heads a bit. You can’t do that, we joined in and stopped playing football.”