The young Blues defender netted his first goal at international level just four minutes into the match in Belgium.
"We had worked on our set-plays," England coach John Peacock told the FA's official website.
"We thought they might be vulnerable at the back post. It's Krystian's first goal for England - I'm delighted for him."
Peacock's side went on to win the game 2-0 - Leeds United striker Danny Rose scoring England's second on 24 minutes.
The England under 17's take-on Belgium on Friday and a win against the hosts will take them a step closer to a place at the World Championships in Korea.
England: Steele (Middlesbrough), Ofori-Twumasi (Chelsea), Pearce (Birmingham City), Spence (West Ham), Mattock (Leicester City), Moses (Crystal Palace), Lansbury (Arsenal), Woods (Chelsea), Plummer (Bristol City), Franks (Middlesbrough), Rose (Leeds United). Subs: Welbeck (Manchester United), Murphy (Arsenal), Taiwo (Chelsea), Smithies (Huddersfield), Gosling (Plymouth Argyle), Porritt (Middlesbrough), Hoyte (Arsenal).