Bruce finally ends Man United hoodoo in landmark game
Bruce – in charge for his 400th game as a manager in the Premier League, making him just the seventh coach to reach that milestone - secured his first ever league victory over the Red Devils at the 23rd attempt.
Longstaff, who hit the crossbar in the first half, hammered home in the 72nd minute at St James' Park as the visitors' run without an away win in the league stretched to eight games, their longest such streak in the top flight since September 1989.
The teenage midfielder's strike saw him become the youngest player to score for the club on his Premier League debut at 19 years and 199 days.
Defeat leaves United with nine points from their opening eight games - their worst start to a league campaign in 30 years. Indeed, since Solskjaer was appointed permanently on March 28, his side have taken just 17 points in 16 matches, the fourth-worst tally among the 17 ever-present teams in that time.