The Belgium coach made no apologies for his side's pragmatic approach and congratulated his team for reaching the knockout stages of the World Cup.
Considered one of the outside favorites entering the World Cup, Belgium claimed three wins in Group H without being overly impressive, also beating Algeria and Russia to set up a date with the USA in the round of 16.
But the 45-year-old coach, whose team played the second half against South Korea with 10 men, said the results were his team's own reward.
"Yet again our patient approach paid off," Wilmots said. "I knew that the Koreans would leave us with a lot of space to play with. My young team had a tendency to push forwards too much at times, so I tried to get them to relax a little.
"It’s no easy task to finish the group stage with nine points. It’s a truly historic achievement for Belgium, and I’d like to congratulate the staff and all the players. We're here to win, not to play beautiful football, and we've accomplished our mission."
Defender Jan Vertonghen scored the match-winning goal in the 78th minute at the Arena Corinthians in Sao Paulo, despite midfielder Steven Defour's red card just before halftime for a reckless, studs-up challenge.
"After scoring, I wanted to share my indescribable joy with our supporters. We feel like they’re really behind us, and that’s important for the squad," Vertonghen said. "Finishing top of the group and pulling off a late win with 10 men is also a real source of satisfaction."