Fewster, seen in our picture scoring for England recently, almost opened the scoring when put through by Cameron Park after just three minutes but his smartly-hit shot was well saved by keeper Dilo.
On 15 minutes Boro were awarded a free kick 25 yards from goal. Park swung it in with his left foot and the ball was met by Ryan Brobbel but his shot again was well saved.
Boro had settled into their passing style, which has served them well this season, and only a last-ditch tackle by Rovers captain Wylie prevented Jordan Jones from racing clear.
The home side then started to get a foothold in the game as the first half wore on. Forrester should have done better with a header that went wide, then Maclaren saw a left-foot curler go narrowly wide of the left-hand post.
Half time: Blackburn U21s 0 Boro U21s 0
Blackburn started the second half as they finished the first and Leutwiler acted swiftly to block Forrester as he broke clear seconds after the restart.
On 50 minutes Boro's Swiss keeper made a great double save first by tipping O'Sullivan's shot wide and then somehow keeping out Forrester's header from the resulting corner.
Boro hit back and Brobbel made a driving run into the heart of the Rovers defence before playing the ball square to Jones but the Northern Ireland youth international couldn't get his shot on target and the ball went well wide.
The breakthrough came on 58 minutes when Wylie slipped under pressure and attempted a hastily-hit backpass back to Dilo. The keeper failed to control the ball and Fewster nipped in smartly to knock the ball into an empty net.
Two minutes later and the lead should have been doubled when Boro skipper Christian Burgess firmly met a Park corner, only to divert it into the side netting. Still Boro drove forward and Jones unleashed a goal-bound fizzer but unfortunately it rebounded back off his team mate Fewster.
The Ewood Park side then started to pile the pressure on as they attempted to fashion an equaliser. Forrester went close with a header that went over the bar and Jayson Leutwiler saved well from Slew before also denying Maclaren's follow up.
Boro still had chances though, although their final ball wasn't quite finding its intended target. On 80 minutes Boro left-back Lewis Sirrell made a great run down the channel but his well-hit shot went high and wide.
Spaniard Hugo Fernandez blotted the home side's copybook when he was dismissed seconds from the end after an off the ball lash out at Fewster.
Boro: Leutwiler, Bennett, Sirrell, Morris (Kneeshaw 70), Burgess (c), Okosieme, Park (Waters 61), Brobbel, Fewster, Jones, Williams (Rhoden 87). Unused subs: Ripley, Peireira
Booked: Bennett (foul)
Blackburn: Dilo, Wylie (c), Bauress, Brown (Hanley 75), Payne, Fernandez, Osawe, O'Sullivan, Forrester (Cham 85), Maclaren, Slew. Unused subs: Raya, Wassi
Booked: Osawe (foul)
Sent Off: Fernandez (violent conduct)
Boro Man of Match: Plaudits go to Andre Bennett and Jordan Jones who both enjoyed good games but the award goes to two players tonight. Centre-back pairing Christian Burgess and Ejiro Okosieme were both outstanding, winning every header and making immaculately-timed last ditch tackles on more than one occasion.