The pair were playing the Julius Baer Generation Cup when Carlsen switched off his screen and left the match without explanation, the latest twist in an apparent feud between the two players.
CNN has reached out to Carlsen’s representatives for comment, but has not heard back.
Earlier this month, the Norwegian withdrew from the Sinquefield Cup in Saint Louis after a surprise defeat to American star Niemann – according to chess24 – the first time he has withdrawn from a tournament in his career.
The 19-year-old admitted to cheating between the ages of 12 and 16, but St. In an interview at the Louis Chess Club, he said he had never cheated at table games.
“I’m telling my truth because I don’t want to be wrong,” Niemann said. “I am proud that I have learned from that mistake, and now I have given everything to chess. I have sacrificed everything for chess.”
The tension between Niemann and Carlsen has shaken the chess community. Niemann said he was removed from the popular website Chess.com after Carlsen’s tweet and that “the entire social media and chess world is completely attacking and undermining me.”
“To see him try to target my absolute hero (Carlsen), try to ruin my reputation, ruin my chess career and do it in such a lighthearted way is really, really disappointing,” he added.
Neither Niemann nor Chess.com responded to CNN’s request for comment.
Rensch continued: “We have invited Hans to provide an explanation and response in hopes of finding a solution to rejoin Chess.com.”
Carlsen and Niemann played two more matches against other opponents, the first following his sudden resignation on Monday. Carlsen is two points behind leader Arjun Erigaisi in the championship standings after eight rounds, while Niemann is four points behind.
“Now it seems very strange. Obviously, it all makes sense, if Hans is supposedly cheating and doesn’t want to play her, but if he’s not (cheating), then he’s very wrong.
“So, I don’t know, we’ll have to see. Again, everyone’s expecting a big bunny with Magnus, but he doesn’t want to play Hans, it seems.”
Levon Aronian, who is competing in the tournament, said that Niemann “has not been the cleanest person when it comes to online chess”, but added that “it is a problem that needs a solution”.
CNN’s Ben Morse contributed reporting.