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.
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 for 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, and hit 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.
