Ronnie "The Rocket" O'Sullivan made a maximum 147 break in the quickest time ever recorded, five minutes and 20 seconds, in the first round of the 1997 World Championship.
O'Sullivan won £147,000 in prize money for the maximum, averaging 8.8 seconds per shot.
O'Sullivan lost in the second round that year, before winning his first world title in 2001. He has won it a further four times since.
Steve Davis looks at the maths behind the 'perfect' 147 with our iWonder guide.
Available to UK users only.