Scotland impressively revived their World Cup 2022 qualification hopes by climbing into a play-off place after a momentous victory in Austria.
Lyndon Dykes' penalty, awarded after a VAR check, gave Steve Clarke's men a lead they clung on to in Vienna.
Stephen O'Donnell - having survived an Austria penalty appeal - and Che Adams had chances to ease the Scots' nerves.
But the visitors stood firm amid intense second-half pressure to collect a priceless and deserved away win.
Coupled with runaway leaders Denmark's 5-0 defeat of Israel, it moves Scotland up two places to second. Clarke's side are a point clear of the Israelis, who visit Hampden next, and four above Austria with four games remaining.
With the three-way fight for the runners-up berth gathering pace, Scotland needed a big performance and to a man they delivered.
Two VAR calls ultimately made the difference in a frantic encounter as Scotland ended the first half having converted a disputed penalty while Austria were incensed they had been deprived one.
There was scarcely an appeal from Adams' team-mates when the striker went to ground while grappling with Martin Hinteregger.
But replays showed the Austrian had a fistful of his jersey, and Dykes rattled the penalty down the middle and under the body of former Kilmarnock goalkeeper Daniel Bachmann.
Hinteregger, already on a booking for clattering Callum McGregor, was fortunate not to be shown a second yellow.
Luck was then on Scotland's side just before half-time when the ball struck O'Donnell's arm as he jostled for a header with Christophe Baumgartner. No penalty was forthcoming and Konrad Laimer skidded a shot wide in the ensuing melee.
The chaotic scene as the sides left the pitch was in keeping with a breathless opening half. The tempo was unrelenting, with Austria making an energetic start as Real Madrid superstar David Alaba marauded down the left and whipped over a succession of crosses.
Marko Arnautovic and Baumgartner fired wide, with the former also botching a header after being picked out unmarked by another Alaba cross.
It was a direct approach that Scotland resisted manfully, with their three centre-backs of Grant Hanley, Jack Hendry and Kieran Tierney standing strong time and again.
Scotland had crafted the clearest opening, with Bachmann palming away a Dykes header from John McGinn's cross, but found themselves pinned back after the break as Austria poured forward fuelled by anger.
Scottish nerves were jangling again when Hanley was booked for grappling with Hinteregger at a corner, with no penalty given as the ball was out of play. The Norwich City defender will miss the Israel next game through suspension, though.
Bachmann almost gifted the visitors a second when he kicked the ground while attempting to clear but Scotland could not capitalise, with O'Donnell's shot blocked.
The keeper redeemed himself with a fantastic sprawling save from O'Donnell's shot after Adams' pass had sent the full-back clear.
Despite dominating possession, Austria did not work Craig Gordon until the closing stages, when the Scotland number one brilliantly batted away a Baumgartner header.
Adams dragged wide at the other end as the hosts went for broke but one goal was enough for Scotland to begin dreaming of a reaching a first World Cup finals since 1998.
Man of the match - Grant Hanley
The centre-back was a colossus as Scotland repelled intense pressureWhat did we learn?
This has the potential to be a campaign-defining result for Scotland against a side who had lost just four of their previous 25 home games and took Italy to extra time in the last 16 of Euro 2020.
Scotland's high point of that tournament - the draw with England at Wembley - was evoked in an another away performance full of quality and sheer dogged spirit.
After a sobering defeat in Denmark and laboured 1-0 win against Moldova, it was the uplifting end to this World Cup triple-header that the nation craved.
Billy Gilmour, at just 20 years old, bossed the midfield and were there stand-outs all over the pitch as Scotland savoured a rare away triumph.
Match stats
Clarke's side have won consecutive matches for the first time since beating Slovakia and Czech Republic in October 2020 - all four games in their two-game winning runs have ended 1-0.Scotland are unbeaten across their last five competitive matches against Austria (W2 D3), winning a competitive away game against them for the first time on Tuesday.Dykes has scored five goals in his last six games for club and country (2 in 3 for Scotland, 3 in 3 for QPR). He has scored in consecutive Scotland games for the first time.Aged 38 years and 250 days, Gordon became the fifth oldest player to feature for the Scotland men's national team - the oldest is David Weir against Spain in October 2010 (40 years and 155 days).Austria have lost consecutive home World Cup qualifiers for the first time, and have failed to score in three successive home matches in all competitions for the first time since February 2008.What's next?
Scotland complete the campaign with two double-headers. First up is Israel at Hampden and the Faroe Islands away on 9 and 12 October.
Then comes a trip to Moldova on 12 November, followed by a potentially seismic Hampden meeting with Denmark three days later.