The first goal arrived inside seven minutes and summed up Brazil's ruthlessness. Scott McKenna held the ball too long under pressure from Rayan, who nicked it and immediately fed Vinícius. The attacker took two touches to round goalkeeper Angus Gunn and rolled home calmly into an empty net. Scotland, clearly rattled, struggled to compose themselves in the opening exchanges.
Vinícius had the ball in the net again shortly afterwards, only for VAR to rule that he had fouled in the build-up. It was a moment of reprieve that Scotland were unable to capitalise on. The Brazilian winger then completed the first-half damage in stoppage time, rising to nod home an inswinging delivery and make it 2-0 at the break. Brazil's total control was reflected in a final expected goals figure of 4.46 against Scotland's 1.13.
Cunha applied the conclusive third in the 60th minute after a slick passing move involving Bruno Guimarães opened the angle for the Manchester United forward, who finished precisely.
Scotland rallied in the closing stages and created several chances. Lewis Ferguson's driven corner caused problems and Scott McTominay met a drilled delivery from Alistair Ralston, only for Alisson Becker to make a sharp near-post save. The late pressure was admirable but changed nothing.
Clarke was brief and blunt in his post-match assessment.
"We made it difficult for ourselves, that's it. We gave them the goals, we gave them the game they wanted. Disappointing."
Asked what comes next, he cut the conversation short.
"I don't even think about that."
Scotland midfielder John McGinn acknowledged both the failings and the uncertainty that follows.
"Gutted obviously. We lose poor goals at poor times against a team that can punish you with quality. We had a few chances but we've got to wait now.
"The lads are gutted, we fell short on quality tonight but we gave it absolutely everything. The lads are empty now.
"It's unlikely [to qualify] but we'll wait and see.
"In moments they hurt you. They allowed us to have the ball and at this level if you make mistakes you get punished. We probably were fortunate to have the goal disallowed.
"It's a bit raw at the minute but we appreciate the support of the fans, we know it's difficult to be there. Hopefully the journey is not over and if we have to go again, we will go again."
Brazil top Group C on seven points and march into the round of 32. Scotland finish third on three points — the same tally as Haiti, who produced a shock 1-0 win over Morocco in the simultaneous Group C match in Atlanta. Whether Scotland's record is sufficient to qualify them among the eight best third-placed sides will not be determined until the remaining group games conclude.
The manner of the defeat — three goals given away to one of the tournament's favourites — will be deeply frustrating for a squad that competed admirably in their first two games.