Brekalo, 20, played all 90 minutes as Croatia began their UEFA EURO 2020 qualifying campaign with a 2-1 victory at home against Azerbaijan.
Brekalo won his first two caps as a substitute in the UEFA Nations League late last year, but his third international outing was his first as a starter. The visitors took a surprise early lead in Zagreb but goals from Borna Barisic and Andrej Kramaric secured three points for the 2018 FIFA World Cup finalists.
Wins for Casteels and Brooks, draw for Uduokhai
With VfL goalkeeper Koen Casteels an unused substitute, Belgium also won their first qualifier, beating Russia 3-1 thanks to an Eden Hazard brace. His VfL defensive colleague, Felix Uduokhai, came off the bench in the 63rd minute of Germany Under-21s' 2-2 friendly draw with their French counterparts.
Wolfsburg centre-back John Anthony Brooks played 90 minutes in USA's 1-0 friendly win against Ecuador, Gyasi Zardes scoring the only goal in Orlando.