The breakthrough came after 65 minutes as Sweden were awarded a penalty after video review.
Sweden controlled the match from the start, holding on to a steady 56% possession throughout the first 45 minutes. "I think it's perfectly natural that we all try to get as much information on each other as we can".
Referee Joel Aguilar had initially deemed Kim Min-woo's challenge on Viktor Claesson fair. The other angle clearly showed there was bare minimum contact by the defender on the ball but he had taken down Claesson.
In the second VAR-awarded penalty of the World Cup, Sweden's 33-year-old captain Andreas Granqvist swept the ball low and left of impressive goalkeeper Cho Hyun-woo. France and Peru have also benefitted from the technology, though the Peruvians missed their penalty kick.
Germany lost their opening match at a World Cup finals for the first time since 1982 after Hirving Lozano scored the winning goal in Moscow.
Korea's players changed numbers in training ahead of Monday's game to confuse Sweden's scouts, Korea coach Shin Tae-yong revealed ahead of the game.
The victory leaves Sweden joint top of the group after Mexico's surprise victory against world champions Germany on Sunday.More news: The high court’s hint on partisan gerrymandering
Sweden's well-organized defense comfortably contained the attack of South Korea, which failed to muster much of a response to Granqvist's goal, and the game petered out over the last 20 minutes. The Swedes just couldn't beat goalkeeper Jo Hyeon-woo until the penalty.
The best three chances fell to Marcus Berg but he was denied by a combination of good goalkeeping, last-ditch defending and uncertainty in front of goal. He also stopped a powerful, dipping header from Ola Toivonen in the second half.
"If he had been part of the team, they probably would have been able to score a lot of goals, but they managed to get through the qualifiers without him", Shin added. He was flanked by Son Heung-min and Hwang Hee-chan. Meanwhile, South Korea looks to rebound against Mexico, with its spirits higher than the clouds.
With Lee Seung-woo entering the match for Kim Shin-wook, South Korea switched to a 4-4-2 formation, but it did little to swing the pendulum.
"I think it'll be tougher than today against [those] two teams.We need to be ready. mentally we need to be there".
During its training for the World Cup, South Korea's national soccer team tried to outsmart a Swedish spy by switching jerseys because-according to the team's coach-"it's very hard for Westerners to distinguish between Asians".
Four years ago, fans pelted the players with candy when they arrived back in Seoul from Brazil.