United's second-string recorded an opening victory in Group C courtesy of Luke Charman's penalty in the closing stages of the clash at the East Riding County FA.
The visitors survived a late attacking surge from Hull in stoppage time as Newcastle held on for maximum points, recording their first clean sheet of the season in the process.
Redfearn told nufc.co.uk: "I thought it was a tough game for us but we played well. I thought we were the better side but Hull City put up a good performance. It was a good game of football but the pitch was difficult and it ended up being a leveller. I think even thought the surface was so poor, the quality of football was really good.
"We created lots of chances again and in the end, it's a penalty but we're doing the right things. You can see the boys are trusting the process. I'm pleased with the clean sheet - it's always important.
"The lads at the back, in midfield and up front are working tirelessly to try and keep a clean sheet in recent weeks. I keep banging on about it and they're probably sick to death of hearing me but it's good.
"If you can nil the opposition, there's always a good chance you can win. You've got to make it difficult for your opponents to score and, apart from the little flurries at the end when they're throwing everyone forward, I can't remember them having a real chance which is great for us as a back four and midfield.
"The front lads worked tirelessly. I thought Luke Charman was outstanding. He scored his penalty but his energy, aggression and holding up the ball was a typical centre forward's performance. It was a great display."
Teenagers Joe White and Elliot Anderson were handed their first full starts for the under-23 squad along with Dylan Stephenson making his debut for United's second-string as a second half substitute.
And, with a number of key Academy players out on loan and on the injury table, Redfearn was heavily pleased with the trio despite their lack of experience at under-23 level.
"We're going in the right direction," Redfearn added. "In the end, we've got three under-18s on the pitch which is a great achievement and great credit to Neil Winskill and Kevin Richardson (under-18 coaches) who have done a great job. It's good news for the club.
"You wouldn't think they hadn't played at this level that much. They've had little cameo roles off the bench but I thought both Joe White and Elliot (Anderson) were excellent. In the first half, when the heat of the battle is high and the tempo is fast, they coped with it and physically.
"We know what they are about technically - they are very gifted kids - but I was pleased they got to the mark. Young Dylan (Stephenson) came on and put himself about too.
"We're light on bodies at the minute. We were missing Mo Sangare and Rosaire Longelo from the other night and Yannick Touré from recent games and we've not got a lot of players.
"However, what is good is these players are stepping up and making their mark which is good for the club."