A place in history beckoned for the leaders of the 137th British Open on Sunday as Greg Norman set out to defend a two-shot lead on the final day.

Norman, who was due to tee off at 2.20pm (1.20pm GMT) alongside defending champion Padraig Harrington, is bidding to become the oldest player to win a major.

At 53, the Australian is five years older than Julius Boros was when he won the 1968 US PGA, seven years older than 'Old' Tom Morris when he secured the last of his four Open titles in 1867 and also seven years older than Jack Nicklaus when he was fitted for his green jacket at the 1986 US Masters.

Harrington, who came from six shots back before beating Sergio Garcia in a play-off last year, is bidding to become the first European in over a century to successfully defend an Open title.

And if KJ Choi, also two shots off the lead, can come through to win he will become the first Asian to win a major tournament.

The potential pool of winners was not restricted to the top three — there were 13 players within six shots of Norman at two-over-par and Camilo Villegas's 65 on Friday offered hope to players further back.

With something vaguely resembling a summer's day threatening to break out in between the showers at Royal Birkdale, conditions were less testing than they had been on the first three days.

But the breeze was still stiff enough for Open organisers to sanction a move to the forward tee at the par four 10th, adding to the three holes that were shortened on Saturday to give the players a better chance to finding the fairways.

It was also still blustery enough to ensure that the nerves of the would-be history-makers would be tested to the maximum down the final stretch.

Norman has attributed his extraordinary renaissance to the happiness he has found in his relationship and recent marriage to tennis legend Chris Evert.

Throughout his opening three rounds he exuded a zen-like calm that certainly gave the impression of a man at peace with himself and the world.

But he knows better than most that even the strongest swings and psyches can unravel in the final round of a major championship.

In 1986 Norman led all four majors after the third round but won only one of them — the Open at Turnberry. It may also have crossed his mind that being remembered as the oldest major winner would be a whole lot better than going down in history as the man who blew a six-shot lead on the final day of the 1996 Masters.

"I've obviously got a chance but there is a lot of golf to be played," was the most he would commit himself to.

If Harrington wins, it will cap a remarkable week that started with him declaring that an injured wrist would have made him pull out of any other tournament.

The Dubliner was bracing himself for a nerve-shredding afternoon.

"It is going to be a day for watching others," he said. "With six shots to make up, last year was more straightfoward. I knew I had to go forward to have a chance of winning."

KJ Choi struggled on the greens on his way to a 75 on Saturday but the South Korean was confident he would get his chance at some stage.

"I enjoy the golf course, I'm comfortable on it. I'm still in a good position," he said.

A frustrating week for Ernie Els looked set to finish on a high. The South African was one under for the day through seven holes after a two at the 201-yard fourth.

Lam Chih-Bing became the first player from Singapore to complete four rounds at the world's oldest major but his weekend was not as enjoyable as it might have been, Saturday's 83 being followed by an 81 on Sunday to leave him at 31 over par.

AFP