The young Magpies trailed by two goals at half time following strikes from Stephen Walker and Ben Liddle, with defender Florian Lejeune playing the opening 45 minutes of the division two clash, the Frenchman's first appearance since sustaining a serious knee injury in April.
It was a game of two halves at Whitley Park as United fought back strongly in the second half and were rewarded for their determined efforts late on, with Jack Young halving the deficit with a wonderful curling strike from distance and - in stoppage time - Oisín McEntee's close-range leveller.
Redfearn told nufc.co.uk: "In the first half, I think I got it wrong, shape-wise. We knew they'd play 4-2-3-1 and then we knew they'd play with five at the back as well. I thought they played really well in the first half and flattened us off.
"We couldn't get a press on but we decided at half time, we want to be positive about everything we do. We took a chance (in the second half), went right up against them and went toe-to-toe. I thought we dominated the second half and if we played ten minutes longer, we would have probably won the game.
"Boro are up there in the league for a reason (third in division two). I think how we set up in the first half made it easier for them. We needed half time, which we got, to change things around and put a positive spin on it.
"We talked about getting the next goal which is always important. Two-nil is always a dodgy score. It took us a while to get the next goal but there were some really grown-up performances from the young kids, particularly who came off the bench.
"If it had finished 2-1, we would have been disappointed but the standard of the performance and the way the lads grasped being positive was a real plus. We went right up against them and asked them questions. They got their rewards for it. It was a strong Boro side and we acquitted ourselves well."
Along with a positive second half display, Redfearn was pleased to see Lejeune make his comeback last night, with the centre-back playing his first game in over six months since suffering an anterior cruciate ligament injury against Crystal Palace.
And, despite a lengthy period on the sidelines, the under-23s head coach thought the Frenchman's presence in the side benefited United's developing youngsters.
