United's U18s returned to winning ways against Middlesbrough thanks to a first-half brace from skipper Oliver Norwood.
The Reds, who went into the game on the back of two draws and a defeat, began brightly at Carrington and went close to taking the lead in the third minute.
Evandro Brandao slid in to meet Stewart right-wing cross but his effort was deflected wide for a United corner. And from the resulting set-piece Scott Wootton saw his low shot deflected away from danger.
Paul McGuinness' side continued to press the visitors, who had not won away all season, and gained the advantage on five minutes.
Having taken Nicky Ajose's pass in his stride, Norwood saw his right-foot shot from the edge of the area take a wicked deflection and fly past the wrong-footed Sam Filler in Boro's goal. It was the perfect belated birthday present for Norwood who had turned 18 just 48 hours earlier.
After pulling off a decent save from Brandao on 12 minutes, Filler was powerless to stop Norwood's glorious free-kick just before the half-hour mark.
Having blazed over from an earlier set-piece, Norwood made no mistake this time, curling an absolute beauty inside Filler's left-hand post from 25 yards. It was Norwood's eighth strike of the season taking him joint top with Kiko Macheda in the Reds' goalscoring charts.
Two minutes later Brandao should have made it three but he sliced his volley, from Brown's looped centre, over the bar as Boro's defence stood watching.
With Rio Ferdinand and Gary Neville watching from the sidelines, United set about building on their two-goal advantage after the restart. But it was Boro who came closest to finding the net at the beginning of the second period when substitute Daniel Hawkins was afforded a free header from three yards out on 54 minutes. Thankfully for United he headed straight at Devlin, who in truth knew little about the save.
Gary Martin headed inches over soon after, before Devlin tipped James Gray's left-foot strike over the bar as Boro ramped up the pressure.