Southgate also underlined his confidence in United striker Marcus Rashford, who endured a frustrating evening alongside Jamie Vardy in a revamped England attack. Germany are out and not many would think that would be a possibility; in the last three minutes, Spain were top of the group; and we saw how close Argentina came.
Southgate and Belgium boss Roberto Martinez made wholesale changes to their starting line-ups in Kaliningrad, with both aware that finishing second offers what appears a more favourable route through the knockout rounds.
England and Belgium share an identical record with two wins from two games in the tournament, and the former Everton manager voiced his admiration for England.
The biggest cheers were reserved for yellow cards, adding to the hilarity of the spectacle.
But with no amnesty on yellow cards until the semi-finals, it's highly unlikely either side will go actively looking for them in order to help their cause for second place.
Manchester City defenders John Stones and Vincent Kompany will be reunited on the game's biggest stage when England face Belgium in the battle to top Group G, but the pair will not discuss football according to the Three Lions centre-back. They wanted to keep the momentum going, winning is a great habit to have.
England's Jordan Pickford is beaten as Belgium's Adnan Januzaj (not pictured) scores their first goal.
Nishino, who took over in April after former coach Vahid Halilhodzic was sacked, stressed he wanted his squad to play a freer, more attacking style in the last 16 against England or Belgium. I think it was planned that we would each play part of the game because we both played the full 90 minutes in the last two games. "We're sorry we didn't play like world champions".
"We tried to take as much of an advantage as we could on a physical level".
Belgium players celebrate after the match.
"When you are leader and a manager you need to make decisions that are right for your group and sometimes those decisions will be criticised and I understand that", England manager Gareth Southgate told reporters.
Having failed to finish off several chances in the first half, Tunisia took six minutes to assert themselves after the restart.
In truth, neither side impressed once an open start tapered off.