AUGUSTA, Ga. - Greg Norman shot a startling 78 yesterday in the greatest collapse in Masters history, giving Nick Faldo his third green jacket and sixth major championship.

It was the sixth time Norman had taken a lead into the final round of one of the Grand Slam events only to lose. But none were as shocking nor as complete as the unraveling that began on the ninth hole and ended in the water in front of the 12th green.

''It's the most nerve-wracking course in the world,'' Faldo said. ''It's as simple as that.''

In that four-hole stretch, Norman went from three strokes ahead to two behind, enabling Faldo to play the kind of golf he does best - methodical, precise, controlled.

Faldo's closing 67 - the lowest score of the day - put him at 12-under-par 276, five strokes ahead of Norman, who started the day with a six-stroke lead. Phil Mickelson finished third at 282.

But the only two players on the course who really mattered were Faldo and Norman.

It was reminiscent of the third-round confrontation between Faldo and Norman at the 1990 British Open at St. Andrews. Playing together, they started the day tied, and Faldo beat him 67 to 76 and went on to win the championship.

Norman would have needed only an even-par round in the final round to win.

''Obviously, I didn't play as well as I could,'' Norman said. ''Things didn't go my way. Nick played solid and steady, and it was all my mistakes.''

While Norman, who has finished second in a major championship eight times, had to carry that history with him over the hills and across the treacherous greens of Augusta, Faldo had the comfort of his past successes.

In 1989, Faldo trailed Scott Hoch by three strokes going to the back nine at Augusta and won in a playoff. The next year, he trailed Raymond Floyd by two strokes going to the last nine and again won in a playoff.

Now, only Jack Nicklaus with six and Arnold Palmer with four have won more Masters than Faldo, and only 10 players in the long history of golf have won more major titles.

It was Faldo's first victory in a major since the 1992 British Open.

Norman's collapse overshadowed a great round of golf by Faldo. No one shot lower than his 67. And no one, except perhaps Norman, played under as much pressure.

Faldo got into the spirit of the showdown between the two dominant golfers of the last decade on the first hole, when he chose to putt out from 2 feet rather than marking. Putting added pressure on Norman's 4-foot par putt. He missed.

Faldo got within three strokes with a birdie on No. 8, then Norman fell apart.

He spun his approach shot back off the ninth green and missed a 10-foot par putt after a poor chip. He missed another 10-footer for par on No. 10 after missing the green left and three-putted No. 11, missing the par putt from 30 inches.

Then on No. 12, for the second day in a row, Norman left his tee shot short in Raes Creek. While he was able to recover for a great bogey on Saturday, this time he made a 5.

Faldo was content to make pars during this stretch and pulled two ahead.

''I had to put my head down and grind as hard as I could,'' Faldo said.

Both players birdied the two par 5s, Nos. 13 and 15. Then Norman ended any chance he had when he hit into the water on the par-3 16th hole.

Faldo finished his fabulous day by making a birdie on No. 18 from out of the fairway bunker.

The previous biggest blown lead in the Masters occurred when Ed Sneed took a five-stroke lead into the final round of the 1979 Masters, won by Fuzzy Zoeller in a playoff with Sneed and Tom Watson.

After a record-tying 63 in the first round and then two gutsy middle rounds of 69 and 71, it looked as if Norman would take a big step toward shedding a reputation started a decade ago, when he led all four of the major championships going to the final ro und and won only one.

Since that notorious Saturday Slam in 1986, Norman has lived with a reputation of not being a closer, of being at his best in a runaway, of not having a swing that would hold up under pressure.