We have seen quite a few China vs China and Korea vs Korea Best of 3s and 5s at Worlds but they never had to face their own region in groupstage.
However in Season 3 we only had 2 groups with 5 teams each. Korea, China and North America each had 1 team in group A and 1 team in Group B while their topseed was already automatically qualified for the Quarterfinals. This wasn't the case for EU tho as they placed last in the Allstar tournament so that meant Lemondogs was placed in Group A while both Gambit and Fnatic had to duke it out in Group B.
In the end both teams advanced tho as Fnatic won the group with a 7-1 record while Gambit tied Korea's Samsung Ozone for 2nd place with a 5-3 record before beating them in a tiebreaker.
This also makes North America the only one of the top 4 regions who haven't played themselves at the World Stage.
