The 19-year-old, who was called up to represent his homeland for the first time just last week, danced into the opposition area before sweeping home a precise finish that fellow American Christian Pulisic would have been proud of.
McKennie - officially the third youngest debutant goalscorer in USMNT history - played 84 minutes of the friendly encounter in Leiria.
McKennie's milestone strike continues a whirlwind year for the young midfielder. He made his Bundesliga debut on the final day of the 2016/17 campaign, was promoted to the Schalke first team during the summer and has made a further seven Bundesliga appearances since.
The Texas native described the moment as a "dream come true" as he looks set to play a pivotal role in both the future of Schalke and the USA national team. Remember the name!