Live: Coverage across BBC TV, BBC Radio and BBC Sport website with further coverage on Red Button, Connected TVs and mobile app.
Topping Group "G" means playing whoever will have finished second in Group H earlier on Thursday - Colombia, Senegal or Japan. They have drawn twice in group stage games, and their last-16 match in the 1990 World Cup saw England win 1-0 after extra-time.
Tunisia had not won a World Cup game since a 3-1 victory over Mexico in 1978.
Reality check or phoney war?
Their final game presented the usual conundrum for teams already through with a game to spare: Do you try to keep the momentum going with your starters, or cycle in reserves to fight for a place and give the regulars a rest?
Victory for either would see them top Group G, and Dier believes familiarity with numerous Belgians on Thursday could help England's cause.
Since winning the World Cup in 1966, England have won just SIX games in knockout global football. Whereas a win against Colombia would guarantee either side a quarter-final clash with Sweden or Switzerland. A second yellow would mean they would be suspended for the round of 16 game.
Southgate has gambled, and time will tell if it paid off.
Momentum is a crucial commodity in tournament football and England sacrificed some here, although that must be qualified by that much-changed starting line-up.
Here's how to watch England vs. Belgium online.
If it was a gamble not to go for the win wholeheartedly then it is one Southgate appears at ease with and he certainly had no regrets about his team selection.
Supreme Court rules in Texas gerrymandering dispute
They would have preferred to see that opinion remain on the books to influence other lower court judges considering similar cases. Enforcing civil rights laws doesn't show hostility to religion", the American Civil Liberties Union said in a statement .
Rashford and Januzaj are undeniably big talents, but they've both had their ups and downs.
Southgate is aware that his captain wants to chase more goals and will not put up with a place on the bench, or waste any scoring opportunities.
'That sums up his luck at the moment, ' Ian Wright, the former Arsenal and England striker, joked to ITV after the full-time whistle. You don't want to see smiles in the changing rooms.
"We want to perform well but I think the priority is not to win", he said.
"There are players on yellow cards". Kane, Jesse Lingard and Raheem Sterling must provide the attacking thrust against Colombia.
Jose Pekerman has refused to entertain the prospect of seeing Colombia´s stuttering World Cup campaign end at the first hurdle.
England now know what awaits them.
Regardless, it's ironic that fair play points - the signifier of the team who, in theory, has played the most within the "spirit of the game" - could be the thing that separates the two sides and lead to an easier run at winning the World Cup. Any underestimation will be heavily punished. This has to be regarded as a plus. I can't imagine a situation where I stand in front of the group of players I have got and start talking to them about anything else.
Southgate and his backroom team will have noted reports from the furnace of Rostov, where temperatures have gone into the 40s.
Harry Kane's involvement is one of the tricky decisions facing Southgate.