Cristiano Ronaldo’s late Nations League winner broke Scotland hearts in Portugal and ensured Steve Clarke's side's dreadful run of form continued.

The visitors took a shock seventh-minute lead thanks to a Scott McTominay header and performed admirably in repelling Portugal’s 16 shots before the break.

Another individual error robbed them of the lead though, when Angus Gunn allowed Bruno Fernandes’ long-range strike to creep into the net after the break.

Ronaldo was introduced at half-time and twice hit a post before finally breaking the barricades, forcing in a delicious Nuno Mendes cross for his 901st career goal.

The defeat - after losing to Poland on Thursday - means Scotland are now without a win in their last eight competitive games, the worst run in their history, and have won just one of the last 14 games.

However, Clarke can take some encouragement from the nature of the performances in the two games in this window, even if they are bottom of their section after Croatia beat Poland 1-0.

With the exception of McTominay’s bullet header, it felt like the entirety of the first half was played in Scottish territory.

Rafael Leao terrorised the left-hand side, creating five fantastic chances either for himself or a team-mate.

Gunn made two fine saves - one from Leao and another from Liverpool forward Diogo Jota - while watching a few other shots fly inches wide.

Every Portuguese roar made Scotland fans wince but the defence somehow stood firm until the break - battered, bruised and punch-drunk but unbreached.

That was until Portugal's first real chance of the second half.

A tame cutback was somewhat scuffed by Fernandes, but Gunn could only palm into his own net. Another individual error to add to a montage from Scotland's recent performances.

Scotland responded well, though. There were penalty shouts from Billy Gilmour and Ryan Christie - both correctly not given - while McTominay thundered a shot into Diogo Costa's midriff.

That was as good as it got for the visitors, though.

Portugal pushed again, led by Ronaldo. His backheel flick unlocked the Scottish defence and put Felix through on goal, but Gunn made amends with a superb save.

Three minutes later, Felix almost scored again with a diving header but Gunn was there again to deny him. Ronaldo hit a post on the follow-up, hitting the upright again in the next phase of play with a fantastic looping header.

Scotland did not heed the warning.

Mendes' teasing cross evaded Jota at the front post, took out Gunn in the middle and was bundled home by a jubilant Ronaldo - his 132nd Portugal goal celebrated just like his first.

From the outset, Scotland were up against it.

Penned back on the edge of their own box, they were forced into playing a back six at times as Bernardo Silva and Fernandes tried to pick holes in the defence.

The Scots stood strong in that low block though. Bodies were thrown on the line but extreme caution was used when tackling after two penalties were conceded on Thursday against Poland.

One problem was ball retention. When Scotland did win the ball, they rarely kept it for very long and struggled to hit either McTominay or Lyndon Dykes.

Occasionally though, they were able to string a passing move together and get it up the pitch.

Another issue for Clarke is the nagging, inevitable feeling they will eventually concede.

That's now 33 goals shipped in 14 games. In the last six, they have been breached after the 85th minute on five occasions. There is a fragility that needs to be addressed.

There's also the small matter of this winless run: they are now without a victory in their last eight competitive fixtures, the longest such run in their history.

With four tough fixtures to come in the Nations League - Croatia home and away, Portugal at Hampden plus a trip to Poland - it doesn't look like ending soon.

As for Ronaldo, what can you say? Maligned after a poor Euros, he was influential here.

He has now scored against 48 different countries and stretched his lead at the top of the all-time international goalscorer chart in men's football.

Surely no-one can catch him.

Scotland head coach Steve Clarke: "Obviously disappointed - it looked for a long period that we'd get something from the game. The effort and the quality the players put in, they deserved to get something.

"I reiterated to the players that we have to understand what part of the cycle we're in, what we're trying to do. We're trying to re-adjust after the summer, we can use these matches to try and build.

"The end goal is to qualify for a tournament. It would be nice to get some points, not to concede late goals but this is the level we're at because we have been a good team. There's been a lot of positives... if you ignore the results."

Scotland midfielder John McGinn: "A sickener at the end but much more like us in terms of level of performance, desire, commitment. Not many people gave us a chance of getting anything but the way we competed was brilliant.

"We're up against a top-class team. Once we conceded the first goal, it would have been easy for us to crumble and go under. We managed to get our foot on the ball and put them on the back foot.

"We've learned a lot from these two games. Individual mistakes in the first game, including my own, cost us. Tonight, it wasn't a case of individual mistakes - the pressure was just too much in the end."