Cristiano Ronaldo came off the bench to score a late winner for Portugal to deny Scotland their first point of their Nations League Group A1 campaign after a 2-1 defeat in Lisbon.
Ronaldo, who scored his 900th career goal in Thursday's win over Croatia, was brought on at half-time at the Estadio da Luz with the home side trailing 1-0 after Scott McTominay's shock seventh-minute header - Scotland's only shot of the first half.
But Ronaldo's introduction sparked Portugal's second-half comeback as his former Manchester United team-mate Bruno Fernandes equalised in the 54th minute.
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The midfielder's leveller was a bit of a gift from Scotland goalkeeper Angus Gunn on Fernandes' 30th birthday as his first-time left-footed shot from the edge of the box squirmed past the Norwich shot-stopper.
But Gunn redeemed himself with three fantastic saves stopping substitute Joao Felix on each occasion, as Ronaldo also hit the post twice in quick succession.
But the 39-year-old was not to be denied as he tapped home a Nuno Mendes cross in the 88th minute for his 901st career goal to make it two wins from two for Portugal as they sit top of Group A1.
It was late heartbreak again for Scotland, though, after they suffered a 97th-minute defeat to Poland at Hampden Park on Thursday.
Steve Clarke's side sit bottom of the group without a point and have now won just once in their last 14 matches, with their sole victory coming against minnows Gibraltar.
Martinez: Scotland gave us a challenge
Portugal head coach Roberto Martinez: "We had a difficult match - it was quite a challenge. Scotland are physical, strong, they attack very fast.
"We have shown the dressing room has a group of more than 11 players who are prepared to help the squad and who give everything to the end."
Clarke: Lessons are harsh at this level
Scotland manager Steve Clarke: "It looked for a long period of time that we would get something from the game. I'm really disappointed for my players. The effort and the quality they put into the game, they deserved to get something from it.
"I reiterated to the players that they have to understand what part of the cycle we are in, what we're trying to do.
"We're trying to re-adjust a little bit after the summer. we can use these matches to try to build and make sure the end goal, as always, is qualification for a tournament for a country like Scotland.
"It would have been nice to get some points and not to concede late goals. But this is the level that we're at because we have been a good team and we've managed to get to the top level of the Nations League. The players understand how difficult it is to get results at this level."
"I think a lot of positives if you can ignore the results, but we're professionals, so it's disappointing to come out of two games where I feel that we played very well and don't don't have anything to show for it.
"Like I said, it's a level where the the lessons are harsh. But it's important - and I spoke to the players in the dressing room - not to be too hard on themselves.
"We decided to change the system for these two matches and I think you see that the players have done good work. That's why I'm so disappointed for them because they put so much into these games."
Modric follows Ronaldo in defying his age
Ronaldo's former Real Madrid team-mate Luka Modric also continues to defy his age as he scored Croatia's winner in a 1-0 victory against Poland just hours before turning 39.
The midfielder struck a second-half free-kick on his 180th appearance for Croatia, meaning Ronaldo is the only European player to have been capped more (214).
The ex-Tottenham player's goal in Osijek sees Croatia move up to second in Group A1 level on points with third-placed Poland, with both sides three points behind leaders Portugal.