The Tigers of Asia were heading out of the competition on Friday until they managed to strike late against Portugal to record a 2-1 victory over Fernando Santos's side.
Hwang Hee-chan's 91st-minute effort moved South Korea onto four points in Group H, qualifying ahead of third-placed Uruguay courtesy of their superior goals scored record.
Here, Sports Mole looks at some reasons for Paulo Bento's side to be confident of progressing to the quarter-finals of the competition in Qatar.
Brazil's recent losses at World Cup
Brazil boss Tite made wholesale changes against Cameroon on Friday, and the South American nation suffered a 1-0 defeat in their final game in the group stage of the competition.
The loss mattered little in terms of the competition, but it was still a setback for the five-time world champions.
Brazil have actually now lost four of their last 10 matches at the World Cup, which is staggering considering that their previous four defeats were spread across 36 games.
Canarinho suffered a 2-1 loss to Belgium in the quarter-finals of the 2018 competition, while they were incredibly beaten 7-1 by Germany in the semi-finals of the 2014 tournament.
Brazil will be the favourites heading into this match, but South Korea will have taken huge confidence from their 2-1 victory over Portugal last time out.
Strong second-half record at the World Cup
Eleven of South Korea's last 12 goals at the World Cup have incredibly arrived in the second half of matches, and four of the last seven have arrived either in the final minute or in stoppage time.
Bento's side netted twice in the second half against Ghana on November 28, with Cho Gue-sung finding the back of the net on two occasions.
Meanwhile, Hee-chan's strike against Portugal on Friday came in the 91st minute, and the effort sent South Korea into the last-16 stage of the competition against the odds.
Brazil are used to keeping the ball and exerting their dominance in the second half of matches, but the Tigers of Asia have demonstrated that they are capable of taking the game until the final whistle.
Return of Hwang Hee-chan
Hee-chan was unable to take part in South Korea's first two matches at the 2022 competition against Uruguay or Ghana due to injury, but he was used off the bench against Portugal.
Son Heung-min deserves huge credit for setting up the winner in the team's last match, but it was a brilliant finish from Hee-chan, who showed his quality in front of goal.
The 26-year-old is yet to find the back of the net for Wolverhampton Wanderers this season, but he has now stuck 10 goals in 50 appearances for his country.
Whether the forward starts is a decision for head coach Bento, but there is a strong chance that he will be involved in some capacity, and he adds real quality to their attack.
South Korea only have four players in their current squad with double figures in terms of goals for the national side, and the Wolves attacker is one of them.
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