Match ends, South Korea 0, Belgium 1.
Ten-man Belgium beat South Korea to top their World Cup group and set up a last-16 tie against the United States.
South Korea needed a win so the onus was on them to attack and they were helped when Steven Defour was sent off for a reckless tackle on Kim Shin-wook.
A Son Heung-Min cross struck the face of the Belgium crossbar but the Asian side struggled to create chances.
And Jan Vertonghen scored the Red Devils' winner when he slotted in after a Divock Origi shot was parried.
Belgium have been criticised for a lack of flair so far in the tournament, but there is little question about their resilience as they have let in just one goal in three games and are unbeaten in their last 13 competitive matches.
Their victory - the first time the Red Devils have won three group games at a World Cup - eliminated a South Korea side who lacked a cutting edge to go with their endeavour.
South Korea boss Hong Myung-Bo apologised to his country's fans after a 4-2 defeat by Algeria in their previous match and his side began with the greater urgency in Sao Paulo.
However, Hong's side might have conceded a spot-kick when Kim Young-gwon cynically blocked Anthony Vanen Borre in an offence which began outside the box and continued inside the penalty area.
And despite all South Korea's early effort they should have gone behind when a Kevin Mirallas shot broke for Dries Mertens, only for the Belgium midfielder to sidefoot high from eight yards with just the keeper to beat.
Hong's side tried to respond, with Ki Sung-yeung's 25-yard shot being turned around the post by keeper Thibaut Courtois.
And from the resulting corner a header back across goal came off Belgium defender Nicolas Lombaerts before being hacked off the line by Defour.
That was almost the last action of the match for Defour as he was soon sent off for a dangerous studs-up tackle which caught Kim on his shin.
With South Korea having the numerical advantage Hong brought on forward Lee Keunho for midfielder Han Kook-young at half-time.
And the substitute striker almost had an immediate impact as he had a shot blocked before heading a cross over, while a Son cross struck the face of the crossbar.
South Korea's need to attack left them exposed at the back and Belgium took advantage.
Origi had looked lively for Belgium after coming on as a substitute and, after his 22-yard strike being parried by keeper Kim Seung-gyu, Vertonghen reacted quickest to slot in the winner.
- 21Kim Seung-gyu
- 12Lee Yong
- 16Ki Sung-yueng
- 20HongBooked at 35mins
- 5Kim Young-Gwon
- 14HanSubstituted forLeeat 45'minutes
- 18Kim Shin-WookSubstituted forKimat 66'minutes
- 13Koo Ja-Cheol
- 9Son Heung-MinSubstituted forJiat 73'minutes
- 22Park Joo-Ho
- 21Vanden Borre
- 16DefourBooked at 44mins
- 15van Buyten
- 19DembéléBooked at 50mins
- 11MirallasSubstituted forE Hazardat 88'minutes
- 20JanuzajSubstituted forChadliat 60'minutes
- 14MertensSubstituted forOrigiat 60'minutes
- 7De Bruyne
- 10E Hazard
- Ben Williams
- Shots on Target
Second Half ends, South Korea 0, Belgium 1.
Foul by Lee Yong (South Korea).
Divock Origi (Belgium) wins a free kick on the left wing.
Foul by Koo Ja-Cheol (South Korea).
Eden Hazard (Belgium) wins a free kick on the left wing.
Delay over. They are ready to continue.
Delay in match Anthony Vanden Borre (Belgium) because of an injury.
Attempt saved. Divock Origi (Belgium) right footed shot from outside the box is saved in the centre of the goal.
Corner, South Korea. Conceded by Thibaut Courtois.
Attempt saved. Lee Keun-Ho (South Korea) right footed shot from the right side of the six yard box is saved in the bottom right corner. Assisted by Lee Chung-Yong with a cross.
Corner, South Korea. Conceded by Daniel van Buyten.
Attempt blocked. Koo Ja-Cheol (South Korea) right footed shot from the right side of the box is blocked. Assisted by Lee Yong.
Attempt saved. Lee Chung-Yong (South Korea) right footed shot from outside the box is saved in the centre of the goal. Assisted by Ji Dong-Won.
Hand ball by Jan Vertonghen (Belgium).
Attempt saved. Eden Hazard (Belgium) right footed shot from the right side of the box is saved in the bottom left corner.
Foul by Lee Chung-Yong (South Korea).
Eden Hazard (Belgium) wins a free kick on the right wing.
Substitution, Belgium. Eden Hazard replaces Kevin Mirallas.
Kim Young-Gwon (South Korea) wins a free kick in the defensive half.