The Red Devils gave themselves the perfect platform for success after taking the lead through Kieran Richardson after just four minutes.
Richardson collected the ball just inside his own half and exchanged passes with Mads Timm before swivelling to fire the ball inside the post from the edge of the area.
The hosts battled valiantly to haul themselves level and United goalkeeper Luke Steele needed to be alert to deny the rampaging James Morrison.
The Boro youngster had his side's best chance before the interval when evading Steele but his goalbound effort was cleared by Lee Lawrence, who had scurried back to block the unguarded goal.
United largely controlled the second period and substitute Sylvan Blake produced a fine save from Ross Turnbull.
In the dying moments of the game, The Red Devils grabbed a decisive second goal as Ben Collett drilled home clinically at the far post.
