Longstaff was drafted into the side as Isaac Hayden started his suspension for the red card he picked up in the 5-0 defeat against Leicester City in the game beforehand.
The emergence of Longstaff was great news for everyone apart from Ki Sung-yueng, who was placed on the bench despite having much more experience than the 19-year-old.
Steve Bruce is surely set to stick with the Longstaff brothers after the international break after they excelled in the heart of midfield both going forward and in defence.
Defensively, the 30-year-old has been poor, averaging 0.3 tackles per game according to WhoScored, as he has failed to disrupt opposing sides as they approach the final third.
Longstaff brought a breath of fresh air to the middle of the park compared to the likes of Ki, and against arguably tougher opposition in Manchester United, he made much more of an impact.
The 19-year-old made one tackle and completed two interceptions according to WhoScored, and played a pivotal role in securing the Magpies’ second victory of the season.
The youngster also had two shots on goal and also completed a single key pass as he excelled in all areas of the pitch against the Red Devils.
Ki is surely at the bottom of the pile now in terms of midfield options, and will certainly find it hard to earn many minutes under Bruce this season.