Going into the game as Group G leaders, England fell behind Belgium in the pecking order when Adnan Januzaj struck early in the second half.
However, should Southgate's men get past Colombia, an inviting quarter-final fixture against Sweden or Switzerland beckons, whilst Roberto Martinez's men will likely have to beat Brazil and France to make their way to the final.
Changed teams, changed performances
Both England and Belgium shook up their teams in a bid to avoid injury, and perhaps even to avoid winning.
There were World Cup debuts for a host of England players including 19-year-old Trent Alexander-Arnold, the likes of Harry Kane, Jesse Lingard and Jordan Henderson all rested by Southgate, who justified not bringing Kane on by saying "If we played Harry Kane for 50 minutes tonight and he takes a whack, we would have been foolish," post-match.
Belgium started the better, Jordan Pickford looking nervous early on as he just about beat away a dipping Youri Tielemans effort.
The young 'keeper seemed to drop the ball in the area minutes later under pressure from Michy Batshuayi, with Gary Cahill scrambling back to clear off the line for England.
Januzaj's moment of magic the difference
It was after this that Belgium, behind England on fair play points, began to tot up a few cards, leaving some wondering whether they were trying to throw the match.
If they were though, Adnan Januzaj clearly hadn't got the message.
A dreary first half had left many contemplating the possibility of a 0-0, Januzaj putting those ideas firmly to bed after 50 minutes as he jinked inside onto his left foot and sent a curling effort away from Pickford's finger-tips and into the top left hand corner.
Danny Welbeck's introduction from the bench meant that every England outfielder has already played some part in the tournament, Welbeck's cameo not proving fruitful as he spurned his only opportunity, shooting wide after a nice ball from Ruben Loftus-Cheek.
England were more slightly tapping than banging on the door for an equaliser at the end, cautiously optimistic that a loss on Thursday evening wasn't the worst thing in the world.
Beat Colombia, and they'll have been proved right.