The young Magpies earned bragging rights over their local rivals after Luke Charman's early penalty and Victor Fernández's second half strike sealed the division two victory at Eppleton Colliery Welfare.
Sunderland were reduced to ten men before half time through Brandon Taylor's red card for handball, allowing the visitors to dictate the majority of possession and goalscoring chances in a dominant display from start to finish.
"I thought it was a good performance," Redfearn told nufc.co.uk. "Sunderland played well in the first half but obviously the sending off made a difference because when you're down to ten men, it's tough to play against but I still thought we deserved to be in front before that.
"We created some really good chances and openings and we could have added more to it. The most pleasing thing is the clean sheet because you can build a lot of things around clean sheets and I've made them aware of that in recent weeks. We put on a performance.
"Victor (Fernández) was a real handful for them and caused them all sorts of problems on the left and Tommy (Allan) on the right. It was fitting that it led through Victor to get the penalty. I thought he took his goal well too.
"I thought Luke (Charman) played very well. It was a good penalty - it took a while and the referee made him wait but he kept his composure and struck it well.
"Strikers always breath on goals, it's a confidence thing. I thought his general play was good - he held the ball up and ran the line well. You've got to remember he was up there on his own but we got midfielders running around him well."
Redfearn was pleased with the professionalism shown from his side as United ought to have added more to the scoreline against a spirited Sunderland side.
Although the 54-year-old was respectful of the Black Cats after playing a large period of the Wear-Tyne encounter with ten men, the head coach feels he is witnessing improvements from his young squad, who lie three points adrift of the division two play-off spots.
He added: "At half time, we said the worst thing for a team with ten men is if they move the ball quick and keep switching it to find the space. I thought we did that well in the second half but the only thing I can say, which I would label in the first half as well, is we were a little bit wasteful.
"You've got give their keeper a bit of credit and I thought Sunderland defended well, throwing bodies in the way and making it difficult. It was one-nil for long enough and they've got to take great credit for that but I thought it was a good, measured performance. Even at nil-nil with eleven versus eleven, I thought we were the better side.
"Everyone played their part and they're doing all right. We're going in the right direction. We've had a couple of hits with results but it's about making this group better and they are starting to learn a bit more. It's our second clean sheet in three games and they're starting to get the message and take things on board.
"Winning is always important because it breeds confidence. With this group, we have a lot missing with players injured or out on loan which makes a difference. In saying that, these lads who turn out have to take a lot of credit. It's a busy schedule with a lot of games one after another and they've really applied themselves in training and games."