A disqualification that was both silly and sad saw Padraig Harrington, the leader by five strokes after three rounds of the Benson and Hedges International Open here, removed from the tournament before the final round began.

It was silly because Harrington had failed in the simplest duty a golf professional has (to sign his card) and sad because it cost the Irishman not just the probability of the £166,600 first prize but also invaluable world ranking points.

The episode was incredible, too, for Harrington is a qualified accountant and claims that he is "the most meticulous checker of a card on the whole European tour". He added: "In fact, I'm twice as meticulous as the next most meticulous man on tour. I check my scores four, five, six times before I hand in my card."

But the card he handed in on Thursday, after the first round, while correct in every mathematical detail, had the fatal flaw of not having his signature, which meant automatic disqualification. And it was a pure fluke that the mistake was discovered.

In the course of building up a five-stroke lead, Harrington had created a record of 64 for the redesigned Belfry course and the host club decided that they wanted that card, plus his others for the tournament, to mount and frame. The European Tour were happy to provide them, but when they were dug out from the recorder's hut it was noticed that Harrington had not signed for his first-round 71.

Events moved swiftly after that. The tournament referee Andy McFee was called in, he found Harrington on the practice ground, hitting shots before going out to do battle with Phillip Price and Jose Maria Olazabal, the two players he led by five shots. Harrington was asked to identify his signature on the card and, of course, he could not.

"Unfortunately," said McFee, "that is a direct breach of Rule 66b and the penalty for that is disqualification."

Harrington, to his extreme credit, agreed totally with the judgement. With a display of professionalism and maturity that could serve as a model for sportsmen everywhere, he refused to blame anyone other than himself. He said: "We know that the responsibility for the card lies solely with yourself. I've been doing it since I was 12 and this is the first time I've failed to sign."

He went on: "I rang all my family and it felt like, `God, I'm ringing round as if there's been a death'. There hasn't been a death? I just haven't won the tournament."

The sequence of events which culminated in Harrington's disqualification began at around 6 p.m. on Thursday. The Irishman and playing partners Michael Campbell and Jamie Spence walked into the recorder's portable cabin after scoring 71, 78 and 77 respectively.

Harrington sat on the left, Campbell in the middle and Spence on the right. Campbell was handed what he thought was his card by Spence, signed it, then realised the figures on it were not his, but Harrington's. He handed the card back, but forgot to say anything about his signature being on the card.

Harrington got the card, checked the figures repeatedly, saw they were correct and, seeing two signatures, handed it over to tournament recorder Annette Hofmann.