Controversial American chess player Hans Niemann is again in the spotlight after a bizarre incident during the US Championship.
Niemann was deep in thought during the endgame of his 12th-round match against fellow grandmaster Sam Sevian, when his opponent suddenly reached across the board and grabbed Niemann's king, pulling the cross from the top of the piece.
"The disrespect just reached its peak," tweeted the tournament leader and former world championship contender Fabiano Caruana.
"Sam decapitated Hans's king."
A visibly-confused Niemann gesticulated his annoyance, before Sevian put the piece back on the wrong square.
The match was then paused as an arbiter was called to resolve the matter.
Touching an opponent's piece in chess without capturing it is highly unusual, but Niemann later said the incident wasn't as dramatic as it first seemed.
"It was just a misunderstanding, nothing too serious," Niemann said.
"We had a cordial conversation afterwards, so there are no hard feelings there."
Niemann said Sevian had noticed the top of the black king was becoming loose and he wanted to fix it.
"So he just picked it up, but I was just a bit annoyed because it was on my time," he said.
"He wanted to glue the piece — I was just very confused."
Niemann went on to win the match, but is out of contention for the title.
The US Championship is being played at the Saint Louis Chess Club, the same venue where Niemann last month recorded a shock win over reigning world champion Magnus Carlsen at the Sinquefield Cup.
Carlsen withdrew from the tournament after that loss, later raising suspicions that Niemann had cheated.
