The South Korean skipper stepped up when his country needed him most, dragging his side forward in the second half of their Group H match against Portugal.
The Taegeuk Warriors went a goal down early on after Diogo Dalot had pulled back a cross from the byline for Ricardo Horta to slot home for the Portuguese.
After Kim Young-gwon equalised on 27 minutes, the momentum swung in the favour of the Koreans.
Son led the charge, repeatedly seeing shots kept out by Diogo Costa in the Portugal goal, as well as having a penalty appeal turned down after his volley had struck the hand of João Cancelo.
But in the dying embers of the match, it was Son who launched the devastating counter-attack from a Portugal corner that ultimately bagged all three points.
With stoppage time running out, the 30-year-old found another gear to bring the ball to the opposition area, holding it up for just long enough before threading through a perfectly weighted pass to substitute Hwang Hee-chan, with the Wolves forward duly blasting home to send the South Korean bench into absolute pandemonium.
With little time left on the clock, the referee soon blew his whistle and an agonising wait for full time in the Ghana v Uruguay match ensued.
But with the Uruguayans unable to find a required third goal, it was South Korea who progressed for the first time since 2010 - somewhat against the odds - and a visibly emotional Son collapsed to the ground as the celebrations erupted in the stadium.
South Korea will next face Group G winners Brazil in the round of 16.
