Magnus Carlsen has resigned from an online match against Hans Niemann after making only one move, reigniting the controversial feud between the two players. The two players met in the Julius Baer Generation Cup on Monday, their first meeting since the American’s victory over Carlsen at the Sinquefield Cup earlier this month. Both players were visible on video link during the live broadcast on Chess24. After making his first move with the black pieces, the world champion promptly resigned and disconnected from the game, with Niemann – who had made two moves with White – following suit soon after. “Magnus Carlsen just resigned. Got up and left,” said the Chess24 commentator and chess grandmaster Tania Sachdev. “Switched off his camera, and that’s all we know right now. We’re going to try to get an update on this.” The 19-year-old Niemann stunned Carlsen by beating him at the $500,000 event in St Louis, but Carlsen then dramatically withdrew from the tournament. He announced his decision in a tweet, alongside a video of the football manager José Mourinho saying: “If I speak, I am in big trouble.” The Norwegian has not commented further, but the world’s best blitz player, Hikaru Nakamura, claimed the withdrawal was because Carlsen suspected Niemann had “probably cheated”. Nakamura also revealed the American had been previously banned by the world’s most popular chess website, Chess.com. Niemann has strenuously denied allegations of cheating at the Sinquefield Cup, but did admit that he had cheated at chess in the past – first as a 12-year-old in an online tournament, and then as a 16-year-old playing unrated games while streaming. “I have never cheated in an over-the-board game,” Niemann said, adding that he was now “clean” and was even prepared to play naked, in “a closed box with zero electronic transmission”, in order to prove his innocence. While both players returned to play their next scheduled matches on Monday, Carlsen’s unexpected move has already shaken up the chess world. “This is unprecedented. I just, I can’t believe it,” Sachdev added. “Did that just happen?” “Magnus [is] just refusing to play against Hans. He will play the tournament, but he is saying ‘I will not play the game against him’. That’s making a very big statement.”