Son and Eriksen played together for over five years at Spurs before the latter moved to Inter Milan in January 2020.
The forward on Saturday evening scored from the penalty spot to earn Paulo Bento's side victory in Goyang before running to a pitchside camera and holding up his fingers to signal 23, the shirt number Erikson wore during his time at Spurs.
"Christian Eriksen, I love you," Son said as he peered into the camera.
The gesture follows a similar one from Belgium striker Romelu Lukaku, who is one of Eriksen’s current team-mates at Inter.
Lukaku, after scoring Belgium’s opening goal against Russia, celebrated by making his way to a pitchside camera and shouting into it: “Chris, Chris - I love you!”
Harry Kane, England captain and another former Spurs team-mate, tweeted on Saturday evening: “Chris. I’m sending all my love to you and your family. Stay strong mate. “