The visitors earned victory with goals from Steven Defour and Kevin Mirallas in the FIFA World Cup qualifying encounter to edge closer to a place at Brazil 2014.
And Strachan admitted Marc Wilmots' side were simply too good for his team.
"That's the best team we've played since I took over. Belgium were magnificent," he said.
"It was like a heavyweight boxer up against a flyweight. They've got speed, height, strength and we don't."
Belgium can now seal their progress by beating Croatia, who sit five points behind them in Group A of the European qualification section following a 1-1 draw against Serbia, when the two face each other on October 11.
Scotland, on the other hand, will use their match against Macedonia on Tuesday to try and lift themselves off the bottom of their pool.
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