The Rumble Stage of the 2021 Mid-Season Invitational has concluded, and with four teams remaining in the event, the Knockout Stage matchups have been set.

League of Legends Championship Series Korea representative DWG KIA selected League of Legends European Championship representative MAD Lions as its opponent, therefore, League of Legends Pro League representative Royal Never Give Up will face off against Pacific Championship Series representative PSG Talon on the other side of the bracket.

However, the teams competing in the Knockout Stage were known well before the bracket was set. League of Legends Circuit Oceania representative Pentanet .GG was eliminated on day 4 of the Rumble Stage after losing its first 7 matches.

On the final day of the Rumble Stage, League of Legends Championship Series representative Cloud9 needed a 2-0 finish and for RNG to beat MAD Lions to force a EU vs. NA tiebreaker for the last spot in the Knockout Stage, but MAD's win over RNG barred C9 from the semifinals.

DWG KIA finished 1st in the Rumble Stage at 8-2, its only pair of losses coming at the hands of Royal Never Give Up. RNG, however, had to settle for 2nd place at 7-3 due to one loss apiece at the hands of PSG Talon, Cloud9, and MAD Lions.

PSG Talon, who was expected to fight C9 for the final Knockout Stage spot, surprised out of the gate and continued to exceed expectations as it was the third team to qualify for the semifinals behind DK and RNG, respectively after defeating PGG in its penultimate Rumble Stage match. 

Despite PSG's Rumble Stage surge, MAD Lions was able to punch its ticket and simultaneously send C9 home alongside PGG with its win over RNG. MAD would go on to lose its last match of the day, played without stakes against C9, to finish 5-5 in the Rumble Stage. The winners of the two Knockout Stage best-of-five series' will play each other in a final best-of-five to see who which team is crowned the MSI 2021 champion.