In his first Scotland appearance for three years, the centre-back headed home from close range in the 35th minute to give Steve Clarke’s team a 1-0 half-time lead in the Group F qualifier for Qatar 2022 at Hampden.
Adding to his three caps, the last of which he picked up in 2018, Souttar was handed a start on the right side of a three-man defence after Jack Hendry failed to recover from a niggling injury.
His goal came from a deep John McGinn corner which found Liam Cooper lurking beyond the far post, the Leeds defender nodding back across goal for the unmarked Souttar to flash his header into the net from six yards.
“It’s a brilliant finish,” said former Scotland forward James McFadden, who knows a thing or two about scoring big goals in the dark blue.
Hampden erupted as the Hearts man ran to the corner flag to celebrate with the Tartan Army, the emotion clear for all to see after three injury-ravaged years had put the brakes on his international career.
Souttar’s previous appearance for his country was memorable for all the wrong reasons when he was sent off against Israel in 2018, and three Achilles tendon ruptures since then had threatened to end his career prematurely.
But the 25-year-old has battled back to full fitness and has been in superb form for the Jambos this season.
He was handed a late call-up by Clarke last Monday after Grant Hanley pulled out with an injury and Scott McTominay was then sent home with a throat infection.
Souttar was an unused sub in Moldova on Friday, but Hendry’s injury in that match meant the Hearts man was next in line for the right centre-back role.
"John has waited a long time and he's came back from a really dark place,” said the manager before kick-off. “It's great to see him on the pitch.”
Former Hearts boss Craig Levein, who managed Souttar at Tynecastle, said the start was "a reward for his tenacity".
With clubmate Craig Gordon behind him, himself creating history on the night by becoming the most capped Hearts player in history, Souttar was a composed figure at the back and played his part along with the Tynecastle goalkeeper as Scotland kept a clean sheet.
It was Che Adams who wrapped up a memorable victory on the counter attack in the 87th minute, surging through in on goal to fire home with a composed right-foot shot into the bottom corner.
Scotland had already qualified for the World Cup play-offs for a spot at Qatar 2022.
However, victory against the previously unbeaten Danes ensures Clarke’s men are seeded for the draw.
The one-leg semi-final tie will be played in March. Souttar deserves to be there.