Toby Alderweireld and Jan Vertonghen both started and played 90 minutes as goals from Dries Mertens and a double from Romelu Lukaku saw the Red Devils home 3-0 against Panama in their Group G opener. Mousa Dembele came off the bench in the 74th minute.
Belgium next face Tunisia in Moscow on Saturday (1pm UK).
Below: Sonny in action against Sweden
Sonny put in a full shift but South Korea didn't register a shot on target as the game was decided by a penalty from Sweden captain Andreas Granqvist awarded after a video assistant referee (VAR) review.