Spirits on Tyneside ebbed at an all-time low heading into the clash with United at St. James' Park.
Positive signs resembled long forgotten friends for Newcastle supporters, who had watched their side win one from seven, hindered by a toothless attack and a struggling new manager in Steve Bruce.
What better occasion then for Bruce to endear himself to supporters by starting not only two academy graduates in the midfield pair, but a pair of Geordie brothers.
On paper you couldn't pick a better combination of midfielders; Matty the more dogged and tenacious type, while Sean imposes himself on the game with elegance and guile.
The reality exceeded expectation as the pair looked confident and synchronised - hardly a surprise given their undoubted youthful contests in local parks and back gardens - making United's midfield look pedestrian at best.
The fairytale was complete when 19-year-old Matty rifled a fabulous long-range winner past goalkeeper David De Gea to send the Toon faithful into raptures.
Having also came through the ranks at Newcastle, Clark can relate to the Longstaffs more than most. And as a close friend of the family, the Blyth Spartans manager was delighted over what he astutely describes as a "unique" situation.
Clark wrote for Tribalfootball.com: "The win has just given the whole city a lift in terms of the result, the performance, the reaction to what's happened at Leicester, and the fact it was involving four local lads, with the two Longstaff brothers, Andy Carroll and Paul Dummett.
"It's great to see and certainly the way the two Longstaff's performed and the story with young Matty on his debut getting the winner, it's just given everyone a huge boost, without going overboard. The fact that we've beat Man United, we've responded to the Leicester loss and the main characters in the story, even though the whole team deserves credit, are the two local lads.
"I spoke to David Longstaff on Sunday and Monday, and obviously the family is unbelievably proud and rightly so. It's unique. You must be so proud to have one son playing for the club but to have two of them, and the way they performed alongside each other in the middle of the pitch, it's amazing."
There is every chance a relegation battle could eventuate for Newcastle, but Clark believes the win over United might prove to be a 'watershed moment' ahead of Saturday's visit to Chelsea.
He continued: "Steve has responded with the rest of the players and it has given everybody something to look forward too.
"Obviously it's a very tough fixture against Chelsea but there's more belief after the last result.
"It's always difficult for a new manager has come in he's seeing new players and giving everyone a clean slate and this might be a watershed moment where everything goes back to basics."