With his dental guard still in his mouth and a slightly queasy feeling in his gut, a shirtless Thomas Cazeneuve was exuberant after checkmating his opponent during a chess boxing bout in Berlin, the world capital of the unusual sport. Just as deft in the movement of his rooks as with his fists, Cazeneuve claimed victory against his Ukrainian challenger after seven alternating rounds of boxing and chess. The match played out before a crowd of curious onlookers drawn to the spectacle of the so-called "Intellectual Fight Club."

Chess boxing was born 16 years ago when its founder Iepe Rubingh brought to life a seemingly far-fetched idea from a French graphic novel, "Cold Equator" by Enki Bilal.

Today, Rubingh has set his sights on introducing chess boxing to the Olympics and even looking at sending robots into battle, as the multidisciplinary sport gains popularity.Daniel Biman (L) and Mohamad Kadija attend a chessboxing fight during an amateur fight event at the Intellectual Fight Club IX in Berlin.

The rules of chess boxing are simple. Three minutes of gentlemanly chess played on a board in the ring is alternated with three-minute bouts of intense boxing over 11 rounds -six of chess, five of boxing. The winner has to earn either a boxing knockout or a checkmate on the chessboard, but either chess boxer can be disqualified for taking too long to make a chess move or by breaking the boxing rules.

"You need to be good in both disciplines, which can be quite complicated. But it's true that one mustn't be afraid of being punched," said Rubingh. The biggest difficulty may be staying lucid to pull off the winning chess move despite the physical demands of boxing.

"It was my toughest fight with a rival who is a total all-rounder, and who has left me exhausted, especially in boxing," said Cazeneuve, 24, a recruitment consultant.

"I held on thanks to my mental strength," he added.

In fact, "60 percent of the winning moves are made on the chessboards and 40 percent in boxing," said Rubingh, a 43-year-old Dutchman. Recalling the sport's gestation, chess-lover Rubingh said it began in 2002, when, after a round of chess that ended in stalemate, he suggested to a friend that they go for a boxing bout in Amsterdam.

"Combined, the two sports are the amalgamation of the most beautiful capacities of human beings to create a type of supreme being," he said.

While it was considered more a curiosity than a real sport in the beginning, chess boxing has gained a strong following, including chess fans who have crossed over to the more physical realm of boxing. Some 3,500 people are card-carrying members of 11 federations in countries including Britain, Iran and Russia.