United's youngsters returned to action after a five-week lull in fixtures, recovering from an early concession to post an impressive victory over Bolton Wanderers.
In teeming rain, the Trotters took an early lead through Adam Blakeman and repeatedly tested Conor Devlin. William Keane levelled matters shortly before half-time, however, and second-half strikes from Cameron Stewart and Tom Thorpe secured an impressive win.
The foundations for victory were laid by Devlin, who made three superb saves in the first period to thwart Mark Davies, Rodrigo and Robbie Blake. The Northern Irishman was beaten after 13 minutes, however, when Blakeman capped a four-man move with a low shot.
United remained on the back foot for long periods, but drew level on 37 minutes when Reece Brown tossed a superb cross into the area, and Keane stooped to power home a clinical close-range header.
The Reds' gameplan was disrupted when Robbie Brady was stretchered off, seemingly with an ankle injury, but a fine pass from Paul Pogba allowed Stewart to drill United into the lead for the first time with a cross-shot which inched inside the post.
Seven minutes later, the game was buried when defender Thorpe joined an attack, latched onto Keane's pass and placed in a fine shot to cap an impressive return to action for Ole Gunnar Solskjaer's side.
United: Devlin; Brown, Wootton, De Laet, Thorpe; Stewart, Tunnicliffe, Vermijl, Pogba, Brady (M Keane 55); W Keane. Subs not used: Coll, Fornasier, Ekangamene, Lingard.