A deflected shot from Bradley in the 32nd minute put Northern Ireland in front against the run of play, and despite having more than 80 per cent possession, Scotland could not find a way back as their winless run stretched to seven games to leave big questions over their Euro 2024 preparation.
For Bradley, it was yet another big moment in a breakthrough season as the Green and White Army enjoyed their first win at Hampden Park in 50 years and the 20-year-old became the first Liverpool player to score for Northern Ireland in 110 years.
“I’m absolutely buzzing,” Bradley told BBC Sport. “I don’t think I could even dream it would go the way it did. To get a 1-0 win, it’s fantastic, a great night all round.
“I was just hoping it would go in and I was buzzing when I’ve seen it go in the top corner. I don’t even know what happened after that.”
Bradley, already the first Liverpool player to turn out for Northern Ireland since Sammy Smith in 1954, became the first Red to score for the country since Billy Lacey in 1914.
“That’s crazy,” Bradley said. “I knew I was the first Northern Ireland player from Liverpool in about 70 years and that’s even madder, to be fair.”
The win, and Bradley’s goal, underlines the sense that this is a new Northern Ireland side building for the future.
They came into the game on the back of an encouraging 1-1 draw away to Romania on Friday, and have held their own against two sides heading to the Euros this summer.
“We’re delighted with the result,” O’Neill said.
“It was a really good performance, a strong performance. Defensively we were excellent. With the team as it is at this minute, the team is maturing, it’s a brilliant result for the lads.
“We’ve played two very good sides who are going to be in Germany in the summer and that gives us a target. We’re not going to be there but it builds confidence, it builds belief in the players and that was the purpose of taking these games.
“Scotland will have different games in the finals where they will not have so much of the ball and that will probably suit them a little bit as well.”
Scotland certainly have a lot to think about going into the summer after a humbling week, having lost 4-0 to Netherlands in Amsterdam on Friday.
“It’s been a frustrating camp,” said Leeds defender Liam Cooper. “Ideally you’d like to go in to May and June on the back of a successful camp but it wasn’t meant to be. We have to get back to ourselves ASAP.
“We didn’t get too high when we got out of the camp and now is not the time to turn on each other and dig each other out. We’ve got to get back to ourselves and work hard to be the team we know we can be.
“Northern Ireland sat in tonight and we’ve got to be prepared to be patient and break them down. I think we got a bit edgy tonight and in the final third we could have been a bit more patient and wait for openings to be there.
“We forced it at times. Those are all things we can improve on and I’m sure the manager knows exactly what we’re doing come May in preparation for the Euros. We’ve got to get our heads down and work hard.”
The Tartan Army were looking for a response following a 4-0 defeat by the Netherlands in Amsterdam on Friday night but were shocked when midfielder Conor Bradley fired in for the visitors after 32 minutes.
The home side picked up the pace after the break but could not break down Michael O’Neill’s determined side, who stood firm to register Northern Ireland’s first win in Mount Florida in almost 50 years.
Scotland have not been on a seven-game winless run since August 2004 to March 2005 and they take on Gibraltar and Finland in June friendlies before they face hosts Germany in the Euro 2024 opener at the Allianz Arena.
Somehow they need to regain their groove or there could be more pain to come.
The Scots had long since booked their place in this summer’s Euros with a terrific qualifying campaign but they were under a bit of pressure following the Dutch defeat.
Manager Steve Clarke made two changes with centre-back Liam Cooper in for Ryan Porteous and striker Lyndon Dykes in for Lawrence Shankland.
There was a youthful look about O’Neill’s side which showed three changes from the team that started in the 1-1 draw in Romania, with former St Johnstone midfielder Ali McCann, Dan Ballard and goalkeeper Bailey Peacock-Farrell returning at the expense of ex-Celtic stopper Conor Hazard, Jordan Thompson and Paddy Lane.
Scotland tried to build some early pressure after midfielder Ryan Christie curled an effort from the edge of the visitors’ area wide of the post, but Northern Ireland were not unduly bothered.
The game drifted along with Peacock-Farrell having next to nothing to do before it took an unexpected turn.
Scotland wing-back Nathan Patterson recovered well to rescue an original mistake when a pass deep inside his own box was intercepted by Bradley and the 20-year-old Liverpool defender turned inside before firing high past goalkeeper Angus Gunn, with the aid of a slight deflection off defender Jack Hendry for his first international goal.
Then Scotland captain Andrew Robertson went off with an injury to be replaced by midfielder Lewis Ferguson and the home side returned to a back four with Kieran Tierney moving to left-back.
Northern Ireland almost doubled their lead on a speedy counter, with Shea Charles guiding the ball just wide, as did Scotland midfielder Scott McTominay – moments later – at the other end.
Boos from the home fans accompanied the half-time whistle.
Scotland started the second half with increased tempo but there still remained a lack of incision and guile and while Jamie Reid fired wide to end a Northern Ireland attack, at least it was an effort on goal.
In the 63rd minute, John McGinn’s free-kick came off Liam Cooper’s shoulder and skipped past the visitors’ goal and the home fans drove their side forward with increasing gusto.
Tierney was finding space down the left but the Scots could not capitalise.
Che Adams and Kenny McLean replaced Dykes and Gilmour in the 68th minute before Shankland and Stuart Armstrong also came on for Christie and McGinn.
Shankland soon had a close-range shot blocked by Brodie Spencer and Peacock-Farrell tipped a Ferguson header over the crossbar for a corner, before Shankland sent a header over and then four added minutes ran out.
Scotland have regressed recently in terms of results but it is this performance that should primarily concern Clarke.
Marcelo Bielsa's men looked like having nothing to show for a dominant first half until Tommy Smith scythed through Helder Costa to give away a 45th-minute penalty that Mateusz Klich converted.
Costa latched on to Stuart Dallas' fine throughball to double the advantage two minutes into the second half and Liam Cooper opened his body to brilliantly finish a cutback from substitute Pablo Hernandez before the hour.
Hernandez struck from outside the box to get in on the act and Patrick Bamford crowned a glorious team move in stoppage time to edge Leeds a point above West Brom at the summit with four games remaining, while Stoke are a point above the drop zone – their goal difference having taken a hammering.
Leeds need a maximum of seven points from their remaining four fixtures to end a 16-year absence from the Premier League.
