Most notable was Peter Hanson's four putt from 15 feet. The Swede might have been thinking birdie when he stood above his first putt, which looked fairly straightforward from the back of the green.

Something bad must have happened to the greenkeeper on Friday night, because he woke up on Saturday morning in an evil mood. A pin tucked behind a bunker is one thing, but cutting a hole at the top of a pyramid is quite another.

Nobody could read it. I sat behind the green and watched the leaders reduced to hip slapping frustration. Hanson simply put his hands in the air and shook his head.

That pin placement may turn out to be a pivotal decision. Defending Champion Padraig Harrington may not have know it at the time, but his par four on the hole effectively gave him two shots on Greg Norman, who leads by two after 54 holes, and KJ Choi, with whom he shares second place.

Stuart Appelby, Hanson's playing partner, also made seven with three puts. Pars for both players would have meant they both stayed in contention. But the pyramid of pain prevailed; there was simply no outwitting it.

England's Ross Fisher, who shot 71 to climb into contention, would have been within three had it not been for his double bogey six on the 10th, a fate shared by Jim Furyk, a pundit's favourite going into the third round.

The effect was crushing for Furyk, who arrived at the 10th tee off the back of two birdies to make the turn in 34. He didn't make another birdie all day and trudged to a back nine 43 that has all but ended his challenge.

The pure difficulty of the hole today went some way to explaining Fredrik Jacobson's air-punching celebration after holing a 15-footer for seven, a score that might usually be gloomily accepted. He was another player for whom the 10th proved a death knell to his Open challenge.

The players will be hoping Birkdale's greenkeeper has a good night's sleep tonight.