Miguel Villagran, Associated Press
U.S. chess boxer David Depto, right, moves a piece with his taped hand during a chess boxing world championship in 2007 against German Frank Stoldt.

BERLIN — Nikolay Sazhin almost knocked out his opponent with a blow to the chin in the second round. But he had to take the queen to win the match.

In front of 1,000 cheering fans one recent Saturday night, Sazhin moved his bishop to go in for the kill and won the world championship of chess boxing, a weird hybrid sport that combines as many as five rounds of pugilism with a game of chess.

The combatants switch back and forth between boxing and chess — repeatedly putting their gloves on and taking them off, so that they can move the pieces around the board without clumsily knocking them over — in a sort of brains-and-brawn biathlon.

"It's the No. 1 thinking game and the No. 1 fighting game," said Iepe Rubingh, the sport's 32-year-old founder.

Rubingh's inspiration was "Cold Equator," a 1992 French comic book in which two heavyweight boxers beat each other's brains out for 12 rounds and then play a 45-hour game of chess.

"That's not functional. So I thought about how it could work," Rubingh said.

In his version, a chessboard is brought into the ring on a table and the combatants play four minutes, after which the board is wheeled off very carefully so that the pieces don't fall over. Then the fighters put on the gloves and trade punches for a round, after which the board is brought back. The pattern is repeated over and over. The chess game can last up to 24 minutes.

If you knock your opponent out, the chess is over, too, and you win the match. If you beat your opponent at chess, then the boxing is over, and you are the victor. In the case of a draw at the chessboard, the boxer with more points in the ring is declared the winner.

Rubingh uses an electronic chessboard that lets spectators watch the action projected onto a pair of large ringside screens.

In 2003, some 800 people turned out in Amsterdam to watch an exhibition match between Rubingh and a friend. "It was a catastrophe. I lost my queen in the second round of chess," he said.

But the loss didn't stop him from pursuing his dream.

The Dutchman returned to Berlin — where he has lived for a decade — and set out to find tough fighters who could also play a good game of chess.

Germany has emerged as a major boxing center, attracting top talent from Eastern Europe. Most of the world's top heavyweight fighters are natives of Russia and Ukraine, and many train in Hamburg.

Rubingh knows he won't be recruiting either boxers or chess players at the top of their game, but he believes there is a deep reservoir of talent among amateur and lower-ranked pro fighters with sharp, tactical minds. One of his first prospects was Frank Stoldt, a 37-year-old Berlin riot policeman and amateur kickboxer. Stoldt was also an obsessive chess player who often lost himself in late-night online matches.

"Both disciplines are aggressive," Stoldt said. He started training at Rubingh's chess boxing gym in Berlin. In November, he won the sport's first world championship in Berlin.

He lost his belt this month to Sazhin, a 19-year-old Russian.

Sazhin learned about the sport while surfing the Internet, and tried out by mailing boxing tapes to Rubingh and playing him in online chess games. Rubingh thinks he could be the first of many chess boxers from a country that has embraced fighters and idolizes chess players like Garry Kasparov and Boris Spassky.

It was long after midnight in a Berlin warehouse when Sazhin and Stoldt entered the ring and sat down at the chessboard.

Stoldt moved quickly to establish a defensive perimeter of pawns, while Sazhin staggered his diagonally. Switching to boxing, Sazhin attacked Stoldt with a relentless series of body blows that left the German exhausted.

Back at the chessboard, Stoldt looked distracted, and he left his queen vulnerable as he scurried to protect an exposed bishop. Sazhin pounced, forcing Stoldt to concede the match.

In addition to the title and the belt, the champion won a cash prize. Rubingh would not disclose how much but said it was mostly symbolic at this point, and "it's nothing compared to professional boxing."

"To see these 120-kilogram (264-pound) guys sitting there playing chess, it's like a photo montage," said 27-year-old chess boxing fan Yarim Fahre. "The different strengths, the tactics — it doesn't go together."

The rules of chess boxing

• A chess boxing match starts at the chessboard. In this version of speed chess, each player has a total of 12 minutes in which to beat his opponent. During a player's turn, the clock is running. When he completes a move he stops his clock, and his opponent's clock starts ticking.

• When the contestants have played four minutes of chess between them, the board game is suspended and they put on their gloves. The boxing is in three-minute rounds. After each boxing round, contestants have a one-minute rest before returning to the chessboard. The contest can last as long as five boxing rounds and six chess rounds.

• If you knock your opponent out, the chess is over, too, and you win the match. If you beat your opponent at chess, then the boxing is over, and you win. In the case of a draw at the chessboard, the boxer with more points in the ring is declared the winner.