Match ends, Slovakia 1, Scotland 0.
Scotland failed to turn dominance into goals as their nine-game unbeaten run ended in Slovakia.
Steve Clarke rested eight of the side that beat Serbia in the Euro 2020 play-off final on Thursday, as the Scots attempted to go 10 without defeat for the first time since 1924.
But Jan Gregus' deflected first-half drive prevented them sealing Nations League promotion with a game to spare.
The Scots are a point clear of Czech Republic in Group B2 with one to play.
Victory for Clarke's side in Israel on Wednesday will win them the section and should they finish level on points with the Czechs, Scotland would finish top because of their better head-to-head record.
This was always going to be about who best balanced the need to freshen up sides suffering emotional and physical exhaustion following 120 minutes on Thursday, with the desire to tap into the elation of progress to the Euro 2020 finals.
While Slovakia caretaker head coach Stefan Tarkovic went with a degree of continuity, making only four changes, Clarke retained only Kieran Tierney, John McGinn and Ryan Christie.
It looked like the home strategy might pay off best as Michal Duris gave recalled goalkeeper Craig Gordon an early test from range.
The danger seemed to awaken the Scots' dormant dancing feet after their raucous celebrations and suddenly Clarke's side were on top, only to fail to score after creating a series of chances.
With Lyndon Dykes suspended, the much-criticised Oli McBurnie had the opportunity to rebut his doubters. But, while the Sheffield United striker showed plenty of endeavour, one chance eluded him after a heavy touch and a header was straight at goalkeeper Marek Rodak.
McBurnie was not the only culprit; Christie, Stuart Armstrong and Liam Palmer also failed to find the target from promising positions.
And Slovakia made the most of their only other first-half opening as Minnesota United midfielder Gregus left Gordon flat-footed with a low 18-yard drive that took a deflection off Kenny McLean.
McLean came close to restoring parity with a header that was pushed away by Rodak as the Slovaks defended in a manner you would expect from a side who knew defeat would relegate them.
Leigh Griffiths was inches from adding more late drama to Scotland's story, but the substitute striker's thumping effort was touched wide by Rodak with the final kick off the ball as Slovakia secured their first group win.
Man of the match - Kieran Tierney
What did we learn?
Scotland can rightfully point to another promising performance, albeit against a side who have been in doldrums until their Euro 2020 play-off final win in Northern Ireland.
Clarke will also take heart from a display from a second-string line-up that suggests he has a degree of strength in depth. However, problems continue in finding a cutting edge up front, especially finding a deputy to Dykes.
Tierney's attacking threat in his more familiar role will reignite the debate about who is best at left-back between the Arsenal man and captain Andy Robertson. Meanwhile, Andrew Considine again did himself proud despite being asked to play in an unfamiliar position on the right of the back three.
- This is just the second time Scotland have a Nations League match (previously P8 W6 D1 L1) and the first time they have failed to score.
- This was Scotland's first defeat since October 2019 against Russia.
- Each of the last three matches between these sides have finished 1-0.
- Goalkeeper Craig Gordon has gone five matches without a clean sheet for Scotland.
- Slovakia last won a home game against Azerbaijan in November 2019.
Scotland head to Israel on Wednesday (19:45 GMT) aiming to win the group and promotion to League A. Slovakia head to Prague needing a win to avoid relegation and could do the Scots a favour against their Czech neighbours.
- 2PekaríkBooked at 56mins
- 14SkriniarBooked at 58mins
- 9MazánBooked at 77mins
- 19KuckaBooked at 44minsSubstituted forLobotkaat 61'minutes
- 8DudaBooked at 65mins
- 17HamsikSubstituted forRusnákat 68'minutesBooked at 88mins
- 21DurisSubstituted forSafrankoat 90+4'minutes
- 23ConsidineSubstituted forGriffithsat 68'minutes
- 7McGinnBooked at 41mins
- 17ArmstrongBooked at 30minsSubstituted forShanklandat 87'minutes
- 11ChristieBooked at 90mins
- István Kovács
- Shots on Target
Second Half ends, Slovakia 1, Scotland 0.
Corner, Scotland. Conceded by Marek Rodák.
Attempt saved. Leigh Griffiths (Scotland) left footed shot from the left side of the box is saved in the bottom right corner. Assisted by Lawrence Shankland with a through ball.
Substitution, Slovakia. Pavol Safranko replaces Michal Duris.
Ryan Christie (Scotland) is shown the yellow card for a bad foul.
Patrik Hrosovsky (Slovakia) wins a free kick in the attacking half.
Foul by Ryan Christie (Scotland).
Attempt saved. Leigh Griffiths (Scotland) left footed shot from outside the box is saved in the bottom left corner. Assisted by Kieran Tierney.
Albert Rusnák (Slovakia) is shown the yellow card for a bad foul.
Foul by Albert Rusnák (Slovakia).
John McGinn (Scotland) wins a free kick in the attacking half.
Foul by Michal Duris (Slovakia).
Liam Cooper (Scotland) wins a free kick in the defensive half.
Substitution, Scotland. Lawrence Shankland replaces Stuart Armstrong.
Offside, Scotland. Kieran Tierney tries a through ball, but Leigh Griffiths is caught offside.
Corner, Scotland. Conceded by Lubomir Satka.
Foul by Albert Rusnák (Slovakia).
John McGinn (Scotland) wins a free kick in the defensive half.
Ondrej Duda (Slovakia) wins a free kick in the defensive half.
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