With Scotland needing a positive result against the away side, it was Belgium who did the scoring at the Hampden Park. As things stand, Steve Clark's men have a very remote chance of featuring in next year's continental tournament.
Contrary to what the scoreline suggests, the Scots began the game showing plenty of purpose against a well-organised Belgium side. However, Belgium punished the home side for a sloppy pass as Romelu Lukaku finished a brisk counter-attack helmed by Kevin De Bruyne.
Going behind after such a promising start sucked the life out of Scotland XI. In spite of them pushing for an equaliser, Roberto Martinez's side seldom looked uncomfortable. Kevin De Bruyne's gate crashing spell of 23 minutes - during which he registered 3 assists - put the Belgian Red Devils in the driver's seat.
In the second half, it was all about damage control for Scotland as they tried to keep the ball moving around. Martinez's side stuck to their plan of hitting the hosts on the counter. To put the icing on the cake, Romelu Lukaku assisted De Bruyne for Belgium's fourth goal of the night.
Without further delay, let's jump straight into 3 reasons how Belgium inflicted the heaviest home defeat in the qualifying stages for Scotland.
#3 Lack of responsibility on the ball hurt Scotland the most
Apart from a period of initial pressure from Scotland, there was never a passage of play where Belgium found it difficult to survive, even when they allowed the hosts to have the ball. The plan was clear, to catch Scotland on the counter.
With Belgium's tactics known to the Scotsmen, they failed to avoid situations which led to the No.1 ranked side scoring against them. Failure to avoid threats from set-pieces were the Tartan Army's biggest undoing in the game. The home side completely switched off after taking the corner, after which De Bruyne expertly slid the ball to Lukaku, who opened the scoring.
Failure to stop the counter-attack with the help of cynical fouls was the most baffling bit of play on the night as Scotland had to avoid simple errors.
The three goals that followed had a similar template, with Scotland losing the ball in open areas and allowing Belgian forwards to break at pace.
While talking about the first goal, Belgium's next two were similar and avoidable too. Only if Scotland remained alert on those set-pieces, the story would have been very different for the home side.
#2 Belgium's clinical finishing was crucial to keep Scotland at bay
This Belgians reaped rewards for being patient at Hampden Park. Never during the game did Martinez's troops look under pressure when the home-crowd got behind their team. The players waited for an error and stuck to the tactical plan chalked out for this challenge.
Belgium's class and composure were personified when they broke the deadlock through Romelu Lukaku. When the players sniffed a chance, they made sure that the move ended with a goal. From that moment on, Scotland chased the game, and the World Cup 2018 semifinalists orchestrated them.
Also, given Scotland's weakest area being the set-pieces, Roberto Martinez shoved all his centre-halves in the opposing box to maximise from that situation. It was a masterstroke as Vermaelen and Toby Alderweireld scored the second and third goal respectively.
For the second half, the Belgians just ensured that the team held a solid shape and played out the 45 minutes. Scotland presented them with another opportunity later in the half which Kevin De Bruyne took with both hands.
On a night where Belgium managed eight shots on target, four of those found the back of the net. Capitalising on their chances was Belgium's biggest takeaway from their game at Hampden Park.
#1 Kevin De Bruyne was too hot to handle for the hosts
Kevin De Bruyne, after a frustrating 2018/19 season where he suffered a string of injuries, has gotten off to a flier this campaign. With just four games into Premier League season, De Bruyne already has five assists to his name. He is undoubtedly one of the best midfielders on the planet at the moment.
Looking as fit as ever and raring to go, De Bruyne is translating his fitness into a rich vein of attacking return. The 28-year-old has continued his Manchester City form with the national side, making Scotland his unfortunate victims.
On the night, the playmaker looked unstoppable, immaculately pinging the ball forward at will. His command on the passes and awareness of movements of other players was sumptuous, and his telepathic relationship with Romelu Lukaku was there for everybody to witness.
In his masterclass at Hampden Park, Kevin De Bruyne assisted three goals and scored one, too. Needless to say, he got the match ball as well.