SOUTHPORT (AFP) - Greg Norman defied the wind, the rain and the march of time to claim the lead of the British Open after his second round at Royal Birkdale on Friday.

The veteran Australian, bidding to become the first man in his fifties to win a major tournament, combined sublime putting with some vintage scrambling as he put together a second level par round of 70.

"It feels a bit like stepping back in time," admitted the 1986 and 1993 champion, while stressing that he was keeping his expectations for the rest of the tournament "realistically low."

Norman's round left him a shot clear of Colombia's Camilo Villegas, who surged up the leaderboard after an extraordinary round of 65, four better than anyone else has managed on a course some of his rivals have denounced as ridiculously tough.

But even the 26-year-old's fireworks could not wrest the limelight away from a man more than twice his age.

Norman, who married tennis legend Chris Evert last month, spends more time on the tennis court than on the golf course these days.

The 53-year-old fits in tournaments when business commitments and injuries allow and he is making his first appearance at the Open since 2005.

But he still knows his way around a links course and he can also still rival the world's best with a putter in his hand, as he proved by sinking a 50-foot putt for birdie on the first green to get to one under par.

Another monster putt enabled him to birdie the short seventh and a three at the eighth cancelled out the damage done by a double bogey at the sixth.

Seven solid pars followed but Norman really had to scrap to keep his round together over the last three holes.

A superb recovery from a greenside bunker, played with his feet outside the trap, salvaged par at the 16th and he needed to hole another two long putts to turn what could have been a 6-5 finish into 5-4.

Playing a couple of groups ahead of Norman, Villegas was making light of the blustery conditions with a total of eight birdies, five of them on the last five holes.

It could have been even better: at the 18th, the Colombian's second shot, from deep rough on the left of the fairway, was destined for the centre of the hole only to bounce off the pin to some 20 feet away.

He holed the birdie putt however to complete a 2-4-3-4-3 finish and a remarkable score for someone who started the day with bogey fives on his first two holes.

"I putted a hundred times better than yesterday. It was a fun round," he said.

Rocco Mediate, Graeme McDowell and Robert Allenby, the overnight leaders and the only players to break par in their opening rounds, all dropped off the pace.

Mediate, who lost an 18-hole play-off to Tiger Woods at last month's US Open was still at one under as he reached the turn.

But the American ran up a double bogey at the 11th to fall back and needed a birdie on the last, where he hit an eight iron to within six inches of the pin, to finish with a 73, which was matched by Northern Ireland's McDowell and Australia's Allenby.

Pre-tournament favourite Sergio Garcia is five shots off the pace after a 73 and his prospects of challenging were not encouraged by the missed tiddlers he missed on the first and 18th greens.

With the cut projected to come at nine over par, Vijay Singh, Ernie Els and Phil Mickelson all knew they had to shoot par or better to stay around for the weekend.

Mark O'Meara, the last man to win a British Open at Royal Birkdale, was already packing his bags, after a second round 77 left him on 11 over.

The 1998 champion's survival chances were wrecked by a double bogey seven on the par five 17th.

"It was pretty good on the front nine but I dropped seven shots on the back, so I'm not a real happy camper," he said.

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