An Olympic boxer takes a punch.
Historically the testing ground for future greats such as Cassius Clay, George Foreman and Lennox Lewis, boxing guarantees some of the most intense action of any Games.
The sport may be familiar to most people in its professional form but Olympic competition remains based around the principles of amateur boxing, where points scoring is just as important as knockout power.
Points are scored when a fighter lands a punch on their opponent's head or midriff. Scores are calculated by a panel of five ringside judges, with the highest and lowest tallies for each fighter removed at the end of each round and the remaining figures averaged.
Those points are then made public, with the winner the fighter who amasses the most points over the course of the contest, or who scores a knockout.
Men's contests, which are grouped according to weight and range from light-flyweight (46-49 kilograms) to super-heavyweight (+ 91kg), are fought over three, three-minute rounds.
London 2012 marks the debut of women's boxing on the Olympic stage, with the women competing in three classes, from flyweight (48-51kg) to middleweight (69-75kg), over four, two-minute rounds.
All boxing tournaments are fought on a straight elimination basis, although there is no third-place contest - instead both losing semi-finalists are given bronze medals.
Boxing was originally considered too dangerous for the modern Games in 1896, although it did make an appearance in 1904 in St Louis because of its popularity in the USA.
It was finally added to the Olympic schedule properly in 1920 and while the United States have won the most medals with over 100, Cuba are also considered to be one of the big forces in amateur boxing.
In Felix Savon and Teofilo Stevenson, Cuba have two of the all-time greats who both won three consecutive Olympic boxing titles during their careers.