Rarely do brains and brawn come together in this way. A Russian has been crowned world champion in the novelty sport of chess boxing that requires equal skill at moving pawns and throwing punches.
Mathematics student Nikolai Sazhin, 19, competing under the name The President, knocked out a 37-year-old German policeman, Frank Stoldt, who served as a peacekeeper in Kosovo until recently.
The loser said he was simply too punch-drunk to fend off checkmate.
"I took a lot of body blows in the fourth round and that affected my concentration. That's why I made a big mistake in the fifth round: I did not see him coming for my king," he said.
Berlin is home to the world's biggest chess-boxing club with about 40 members and it was in an old freight station that the two men settled the matter in the early hours of Sunday.
The light-heavyweight match began over a chess board set up on a low table in the middle of a boxing ring.
Stripped to their waists, wearing towels around their shoulders and headphones playing the lulling sound of a moving train to drown out the baying crowd, the men played for four minutes.
Then off came their reading glasses and on went the gloves and the gum shields.
For three minutes they punched each other and then, when the bell went, the chess board was back in the ring and they picked up the gentlemanly game where they had left off.
"This is the hard part; you are out of breath but you have to keep your wits about you," said David Steppeler, a 33-year-old instructor at the local chess-boxing club.
"It is especially hard for the one who has to play first. He can easily make a false move, and in chess this is fatal. So in training we toughen people by making them do push-ups between every two chess moves."
A chess boxing match consists of six rounds of chess and five in the ring but it can also end suddenly in knockout or checkmate.
Alternatively, one of the players can be disqualified for taking too long to make his move in the chess rounds or breaking the boxing rules.
The weekend saw two matches apart from the world title bout and some of the competitors might have felt equally at home in a Mensa club meeting. One had a doctorate in biochemistry, another held a degree in political science and two were teachers.
The best in the world of chess boxing score somewhere between 1,700 and 2,000 points on the Elo chess-rating system, putting them on a par with those who perform well in the game at club level.
Perhaps fittingly, the sport had its beginnings in a comic strip by French author Enki Bilal entitled Equator Cold, which hit the shelves in 1992.
The last work in Mr. Bilal's The Nikipol Trilogy features a blood-stained chess-boxing battle set in an apocalyptic city in 2034.
In 2003, young Dutch artist Iepe Rubingh decided to bring it all to life, but with less brutality, and organized the first match.
"But the way we do it is not as dark as it was in the comic strip. For me the thing is to channel your violence, to control it. Hence the marriage between boxing and chess," said Mr. Rubingh, who is the president of the international federation of chess boxing.
Jelena, a French student in the crowd, said the idea seemed "a bit mad" at first. "But, in fact, it's really gripping to watch."