0918 GMT June 23, 2018
A spate of withdrawals looked to have taken the edge of Friday's encounter, yet an experimental and inexperienced side made the most of its opportunity to shine in a spirited 0-0 draw, PA Sport reported.
Wembley witnessed England's most entertaining performance in months as Southgate handed five players their senior bow, including man-of-the-match Ruben Loftus-Cheek and outstanding goalkeeper Jordan Pickford.
"It was an interesting game," Southgate said.
"Their system caused us some problems with (Mesut) Ozil and (Leroy) Sane dropping deeper, and our system caused them problems with our number eights.
"It was a bit end-to-end, but I thought we showed real composure with the ball throughout the team.
"Second half, we were tactically a bit better without the ball and didn't concede so many chances.
"Maybe they had another level to go to, but I think everyone knows what we are missing as well.
"And then I think individually some really top debuts and some really encouraging performances."
Tammy Abraham, Joe Gomez and Jack Cork joined Pickford and Loftus-Cheek in making their debuts, with the latter particularly impressive against the World Cup holder.
"Well, he's a player I've watched do that from Under-16 level," Southgate said of the Chelsea midfielder, currently on loan at Crystal Palace.
"Despite his size, appearance and the way he plays, he's not hugely confident at times and I think tonight it took him 10 minutes to have a look around him and think 'all right, OK, I can do this'.
"He's got so many good attributes, top attributes, and that's why we put him into the team.
"I don't think the wider public may be as aware of him – you would have to follow very closely – but we believe in him and believe in the others we played.
"I'm really not surprised with what they've done because they've shown that previously in the younger ages, they've shown that this week in training. There's been an energy about the group."