Sweden marked their first appearance in the World Cup after 12 years by beating South Korea thanks to a penalty from captain Andreas Granqvist that was awarded after a video assistant referee (VAR) review.
There was a short delay for Kim Min-woo's foul on Viktor Claesson to be analysed on video and for the referee to point to the spot before Granqvist sent goalkeeper Cho Hyun-woo the wrong way.
Sweden, who join Mexico at the top of Group F on three points, created the better chances in Nizhny Novgorod, reports BBc.
Marcus Berg should have scored midway through the first half but his close range shot was beaten away by Cho, while South Korea did not manage a single shot on target.
In a scrappy game, Cho also saved well from Ola Toivonen's header following a free-kick.
South Korea, competing in their ninth successive World Cup, were disappointing and the closest they came to scoring was when Koo Ja-cheol headed into the side netting.
The result means Mexico, 1-0 winners over world champions Germany on Sunday, and Sweden have a three-point lead after the first round of matches in Group F.