How big could this be for Newcastle United?
On a day when questions were asked of Eddie Howe's side they managed to answer them all in a scrappy but deserved narrow victory - thanks to Jonjo Shelvey's winning goal with 15 minutes left.
First, they stepped up to the plate and matched Leeds' intensity after surviving some first half scares.
Go here for all the latest Newcastle United news
Then after keeping the home side at bay, they created the magic moment after Javier Manquillo's clever forward run.
But most importantly, after dropping so many points this season, once they went ahead they held on to that precious lead.
Yes, they should have had a penalty after Allan Saint-Maximin was upended late on and yes they should have doubled the lead through Joe Willock shortly after that.
However, in the end, it mattered not.
The scenes in front of the away end - as shirts were tossed into Geordie fans - made this look like Newcastle had reached a cup final.
But as they closed the gap to just a point on Norwich above them they will jet off to the Middle East for a warm weather training camp knowing they are still alive in the battle against the drop.
Newcastle's first glimpse of goal came after four minutes when Joe Willock picked out Joelinton but he scooped it high and wide with Illan Meslier under no pressure.
Three minutes later, Chris Wood forced a corner as the Magpies tried to make the most of Leeds' high line and catch them on the break but the set-piece came to nothing.
However, with 10 minutes gone, Newcastle were indebted to Martin Dubravka after he made a brilliant block to deny Mateusz Klich after the ball was cut back to him right in front of goal.
Klich looked odds on to finish before Dubravka's sprawling save kept the game level and he pounced on the rebound as if his life depended on it.
Seconds later, both sets of supporters chanted the name of Gary Speed in the 11th minute to celebrate the life of the man regarded a legend by both clubs.
With 16 minutes played Newcastle were afforded another opening when Saint-Maximin wriggled around the defence but his effort was wayward.
Poland international Klich found another opening on 19 minutes but his effort swerved wide of the post after Newcastle were exposed again.
Moments later, Raphinha struck a wild shot over the bar after the home side found another way through.
A tame shot from Ryan Fraser resulted in a corner on 28 minutes before the ball was half-cleared and fell for Jonjo Shelvey.
The Toon midfielder struck it with venom but Meslier parried it to his right.
Newcastle were forced into a change four minutes before the break when Joelinton went off with a knee injury.
The £40million signing was replaced by Sean Longstaff as Newcastle were forced to tweak their midfield.
Despite having nine goal attempts, Newcastle lacked the decisive touch where and when it mattered and Leeds looked the more dangerous of the two teams.
The sides went in locked at 0-0 at half-time with the game wide open.
Leeds came at Newcastle again after the break but Daniel James' cross rolled wide of the bac post with nobody connecting.
Then things started to get scrappy.
First James was shown the yellow card for a late challenge on Dubravka which saw the Slovakia international floored.
Saint-Maximin was booked for persistent fouling before Leeds began protesting about Newcastle's time wasting.
Just after the hour mark Dummett, who had been given a torrid time by Raphinha, went off with an injury.
Referee Chris Kavanagh handed the Geordie defender a yellow card for time-wasting as he went off to be replaced by Manquillo.
The injury woe continued for Howe when Jamaal Lascelles was taken off on 68 minutes and replaced by Ciaran Clark.
Newcastle were handed a great chance with 72 minutes gone when Wood laid it off to Longstaff
Yet the midfielder's effort flew wide of the target and Leeds survived the danger.
Substitute Manquillo won a free-kick with 15 minutes to go.
It looked like Trippier would step up and take it but despite striding forward he left it for Shelvey.
And the United midfielder's curling effort skidded up off the turf to beat Meslier to spark ecstatic scenes in the away end.
Shelvey sprinted over to the travelling Geordies to celebrate and leave Leeds fans absolutely stunned.
Newcastle should have had a penalty with eight minutes left as Saint-Maximin was upended in the box by Robin Koch.
The decision was looked at again by VAR but they stuck with the original verdict.
Saint-Maximin then picked out Fraser for a good chance on 87 minutes but his effort went wide.
The Frenchman then found Willock in the box but his effort was saved by the keeper.
But in the end a second goal wasn't needed as Howe won his first away game in charge and only his second since arriving in November,
With 17 games left, Newcastle have more than just hope - especially if they round off the transfer window in style.
For the latest Newcastle news direct to your inbox, go here to sign up to our free newsletter
