Every Open has one. In fact it might be argued that unless a total unknown leads in rounds one or two, the Open concerned is not a proper championship. By that criterion, the Australian Open, at the Metropolitan club in Melbourne, is very definitely proper.

After 36 holes it is being led by Nick O'Hern, a name fit to be ranked with some other unknowns who have led other Opens, like Wayne Stephens, Bill Longmuir and David Huish, all of them fleetingly famous on the championship courses of Britain.

In fact, when it comes to unknowns, O'Hern is not so much anonymous as invisible. Last year he made just one cut on the Australian tour and won £200.91. This year he made the cut last week, came through this week's qualifying event for the Open and now leads with an amazing 11under par total of 133.

But he is only one in front of Lee Westwood, a young man who is rapidly acquiring one of the highest profiles in golf. The Worksop 24-year-old birdied the last two holes for a six-under par 66, for a 10-under total of 134. He, in turn, is one ahead of Greg Norman and when O'Hern looks around he will see some truly formidable figures over his shoulder.

Westwood had seven birdies all told, but the one that pleased him most came off his worst drive of the day. He hooked it into thick rough on the 18th and, after deliberating for some time, decided on a nine iron.

This is a club he would normally use for a 140-yard shot: this one travelled 188 yards, and by design. "I knew we would get a flier," said Westwood, "and I knew when it landed it would bounce more than usual." The ball, as expected, ran up to eight feet and was duly holed.

Interviewed before the tournament Westwood told the local press that he hoped to win. Yesterday he confirmed that, adding: "Obviously Greg is still around. You can't take the world number one too lightly when he's only one behind you."

O'Hern's is, in many ways, a heart-warming story. He cannot really afford to play the Tour, but his wife, Alana, a graphic designer, is able to support them both, even to the extent of occasionally caddying for her husband.

She was unable, though, to get the day off for the first round and so O'Hern carried his own bag. He gave himself some good lines on the greens, too, finishing with eight successive single putt greens, totalling only 24.

The couple live in Perth, 1,600 miles away, and Alana caught the red-eye flight yesterday morning, arriving in Melbourne at 5 a.m. That meant that O'Hern had to get up at 4 a.m. to meet her, then go back to bed for an hour before his 10 a.m. tee time. He then had a bogey-free 66 and leads an important tournament for the first time in his life.

Greg Norman, the winner for the last two years, is going for an unprecedented three-in-a-row. Jack Nicklaus, who won this championship six times, included in that total four in five years, but never did the hat-trick. Norman had five birdies and an eagle yesterday in his 67, hitting a three-wood second at the long sixth 243 yards on to the green. "I'm not hitting it quite right yet," said Norman, "but with the help of the putter I got the job done."

Darren Clarke, after a 71 for 143, would need two sensational rounds to win and, as he looks a tired man at the end of a long season, there is little chance of that. "The greens are so fast," he said yesterday, "that everything is magnified. If you get the pace wrong just fractionally it can really hurt you."

So, too, can the honesty so essential to the playing of the game. On the par four fifth Clarke, having hit a six-iron second to seven feet, had a birdie putt - at least until his ball moved after he had addressed it. No one else saw it, but Clarke called the penalty on himself regardless and the fates then allowed him to hole what had now become a par putt.

(Australian unless stated)

133 - N O'Hern 67 66.

134 - L Westwood (Eng) 68 66.

135 - G Norman 68 67.

136 - B Partridge 67 69, S Allan 66 70.

137 - P Mickelson (US) 69 68.

138 - S Leaney 66 72.

139 - A Coltart (Sco) 65 74, S Appleby 69 70, P Devenport (NZ) 69 70.

140 - C Parry 70 70, R Damron (US) 68 72, P Lonard 63 77.

141 - G Evans (Brit) 70 71, P Senior 68 73.

143 - D Clarke (N Ire) 72 71.