GREG NORMAN confidently increased his lead to four strokes when the half way stage of the 60th US Masters was reached in swirling winds at Augusta National yesterday. But the warm glow of a 12 under par total of 132 would have been chilled somewhat by the sight of an old adversary, Nick Faldo, lurking with most definite intent just below him on the leaderboard.

The so called Shark, who had blitzed the opposition with a marvellous 63 on Thursday, coped admirably with the daunting task of protecting his position by shooting a fine 69. But Faldo did considerably better. Not only did his 67 allow him to break clear of a group of five sharing sixth place overnight: it lifted him into the last two ball today as Norman's partner in the third round.

While Phil Mickelson, second overnight, appeared to buckle in the heat of yesterday's battle, South Africa's David Frost made dramatic progress to join the lefthander in a share of third place, two strokes behind Faldo. And all the while, there was the realisation that a notoriously demanding course offered a lifeline to several other challengers further down the order.

"Anything can happen here," warned the 1991 champion, Ian Woosnam, as he contemplated Norman's advantage at the close of play. "In my view, six or seven strokes would he a realistic gap at the halfway stage." Whether Woosnam, who shot a 69 for 141, could make up nine strokes on a player of the Australian's calibre, however, is an entirely different matter.

The critical development was the renewal of rivalry between players who had a memorable clash in the 1990 British Open at St Andrews. Sharing the top of the leaderboard at the halfway stage, their third round duel in that contest developed into a crushing triumph for Faldo, who broke Norman's spirit with a 67 to his opponent's 76.

Then there was their meeting in a play off for the Johnnie Walker World Championship in Jamaica in 1992, when Faldo again emerged victorious. But Norman had a revenge of sorts a year later at Royal St George's where though they didn't actually play together, the Shark had the satisfaction of emphatically outscoring his erstwhile tormentor on the way to the title.

Both were being suitably coy last night about the impending confrontation. "It doesn't really bother me who is in contention," said Norman. "All the guys on the leaderboard have played well enough to guarantee that they're not going to disappear over the weekend." Meanwhile, Faldo said: "My concern will be to keep my head down and worry about my own game. That situation at St Andrews was blown out of proportion: all I was trying to do was win the Open."

When the cut was made on 146, two over par, six Europeans survived - Faldo, Woosnam, Alexander Cejka, Bernhard Langer, Colin Montgomerie and Seve Ballesteros. David Gilford, who had made such a promising start with a 69 on Thursday, crashed to a 78 and missed survival by a tantalising, one stroke margin.

Such considerations were of no more than academic interest, however, to the defending champion Ben Crenshaw, who departed the scene on 151. Fred Couples, on the other hand, rallied admirably, when a sparkling 68, no fewer than 10 strokes better than his opening round, secured his survival on the limit.

Meanwhile, the treacherous 18th was the scene of high drama for two of the European survivors. In fact birdies there tilted the balance in favour of the world number two, Montgomerie, and the twice former champion, Ballesteros, who continued to defy the odds imposed by dreadfully erratic driving.

Montgomerie seemed destined far yet another Masters disappointment when a double bogey six at the 10th left him four over par for the championship. His problem was that gusting winds among the towering pines, caused him to hit his approach almost 40 yards through the green. From there, the big Scot took two to get onto the putting surface and then proceeded to two putt from eight feet.

Some of the damage was repaired by birdies at the 13th and 14th but Montgomerie was back in serious trouble again after a bogey six at the long 15th. So, the 405 yard 18th was his only hope With a beautifully controlled fade past the fairway bunkers on the left, he had 128 yards to the flag.

Perfect execution of the wedge shot placed him four feet from the pin and the putt went down for a hugely relieving birdie.

"God! This bloody place," Montgomerie exclaimed after an extremely trying day in the sun. Clearly, memories were still fresh of a grim experience here two years ago when he missed the cut after an opening 77.

Ballesteros had a remarkably similar finish. He, too, needed to birdie the 18th for an aggregate of 146 and he was further back than the Scot. With a nine iron approach, however, the Spaniard left the ball three feet from the pin and, as had been the case with his short game through all his travails, the putter did its job.

Woosnam was upbeat after breaking 70 for an eighth time in 32 rounds at Augusta. His 69 owed much to a splendid run from the short 12th which saw him card four birdies over the closing seven holes. A 25 footer found the target for a two at the short 12th; he pitched to three feet from off the left of the long 13th for a four; set up a two putt birdie at the long 15th by reaching the green with a two iron and went on to hit a sandwedge to four feet for another birdie at the 17th.

Against that background, it was no surprise to learn that the back spasm which inhibited him earlier this week had eased appreciably. "It's a spasm that comes against me from time to time and the main effect in on my driving," he said. "I'm not as consistent off the tee as I need to be around here."

Norman offered fresh hope to his would be challengers when he slipped to eight under par for the tournament by bunkering his tee shot at the short fourth. It is to his credit, however, that he had the patience to wait for birdie opportunities. Conservative play is alien to his golfing make up yet it was imperative in these circumstances.

The pay off came in the shape of a birdie at the long eighth where he chipped to four feet. And he held that position into Amen Corner, though, by his own estimation, it meant sinking the fastest, four foot putt he had ever encountered - for a par on the 11th. "I took the putter head back no more than an inch and off it went: I've never seen anything move so quickly," he said.

Norman then had a stroke of good for tune at the 12th where misjudgement of the wind caused his ball to come up short of the target where it held on the bank above Rae's Creek, just as had happened to Fred Couples on his way to victory in 1992. "Sometimes you get a break in this game and, yes, I got one there," he admitted.

The Shark then proceeded to ride his luck, carding a two putt birdie at the long 13th and another birdie at the long 15th where he got up and down from a greenside trap. But the crowning glory of his round was a marvellous three at the 18th where, off a huge drive, he needed only a sandwedge to leave the ball four feet from the pin.

Faldo's round was considerably tidier, though he started with a bogey at the first where he drove into the fairway bunker. From there, he covered the remaining holes in six under par, birdies at the second, seventh, 10th, 13th, 15th and 18th, and not a bogey in sight.

He scrambled brilliantly, which meant that his mallet putter was in fine working order. This was particularly evident at the 13th, which he single pulled from eight feet and the 15th where he recovered from off the back of the green to six feet. And from a wedge approach at the last, Faldo sank a testing, downhill effort of 12 feet. Quite brilliant.

Listening to him afterwards, one sensed that he couldn't wait to continue the battle with a course that demands "amazing accuracy, shot making and perfect touch." Meanwhile it is interesting to recall developments on the four previous occasions when Norman was the outright leader at the halfway stage of a major championship. He lost three of them but was a runaway, five stroke winner of the 1986 British Open at Turnberry.