The only person who could defeat Magnus Carlsen was himself.

Sven Magnus Øen Carlsen[a] (born 30 November 1990) is a Norwegian chess grandmaster. Carlsen is a five-time World Chess Champion, the reigning five-time World Rapid Chess Champion, the reigning seven-time World Blitz Chess Champion, and the reigning Chess World Cup Champion. He has held the No. 1 position in the FIDE world chess rankings since 1 July 2011 and trails only Garry Kasparov in time spent as the highest-rated player in the world, while holding the record for longest consecutive reign. His peak rating of 2882 is the highest in history. He also holds the record for the longest unbeaten streak at an elite level in classical chess at 125 games.