Major golf championships present two large psychological barriers to great players.

When a potential champion is young and trying to establish his golfing identity, perhaps establish it in his own mind, he must surmount the mental devils and devious tricks of self-defeat to which flesh is heir.

The second sort of barrier is built over the years by those players who are not able to get over the first hurdle. The more they fail to win their first major championship, more inexorable their subsequent failures seem and their task becomes near-hopeless.

Hal Sutton, who leads the PGA championship by two strokes over Ben Crenshaw with a 65-66-72--203 after three rounds, stands at that first barrier. He'll enter Sunday's final round here at Riviera wondering what heretofore unsuspected monsters will rise from his unconscious and complicate all the arduous golfing tortures he must confront.

Even today, in the blast-furnace heat of Southern California, which recorded its hottest Aug. 6 in 100 years--105 degrees at the downtown Los Angeles Civic Center--Sutton was in constant danger of watching his own wheels come off. Twice, he made a pair of ugly bogeys (at the first and fourth, and at the 14th and 15th), and twice, when he seemed about to crash back into the pack, Sutton pulled himself together rapidly with birdies (at the sixth and eighth, and at the 17th).

"I got mad with myself both times and said, 'Come on, let's not let this happen,' " said Sutton, who, in his previous tournament, at Williamsburg, blew a six-shot final-day lead with a closing 77.

Crenshaw, who currently stands in his all-too familiar position, second place, must confront the other predicament. For 11 seasons, he has mastered the brutal art of playing just well enough not to win one of the major crowns he wants most.

Other than Crenshaw, only one player is within five shots of Sutton--John Fought, a two-time PGA Tour winner whose sensible, even-par 71 leaves him four shots back at six-under-par 207.

"It may only take two or three under (a 68 or 69) for somebody to come out of the pack and win tomorrow," said Fought. "The collar starts tightening when the whole thing is on the line . . . Winning your first major, sometimes that's a big hump to get over."

In a trio at 208 are Bruce Lietzke (70), U.S. Open champion Larry Nelson (68) and Pat McGowan (73). The crowd's choice, Jack Nicklaus, who undid four birdies with four bogeys in a 71, is part of a seventh-place quartet at 207 with Scott Simpson, Buddy Whitten (73) and Jay Haas. Perhaps Lietze spoke for all of them when he said, "My chances are slim because Mr. Sutton is playing very well. And so is Crenshaw . . . But anybody who can get it to around eight under par certainly still has a respectable chance."

This afternoon, as the Santa Ana winds blew early and the ocean breezes replaced them later, as the Riviera greens burned and baked until, in Lietze's words, "They were so near death you'd have to call some of them 'browns,' " Crenshaw frequently had the runner-up look he's worn five times before--twice each at the Masters and British Open, and once in the PGA.

If Sutton's two major challengers are Crenshaw and himself, then he may have only himself to beat. Unless Crenshaw gets a better handle on himself than he had today, Gentle Ben may do the rest for him.

At the easy eighth hole, Crenshaw was mightily distracted and angered by a media dolt who made a racket just as the golfer reached the apex of his backswing. Crenshaw hit a half-dozen homely drives this day, but nothing approached his screaming flinch hook. Crenshaw threw his tee at the man and snapped, "Can't you be still?" After finishing the hole with an up-and-down save of bogey, Crenshaw shook his head and told a couple of reporters, "I don't want to hurt anybody, but I think it was that Mutual Radio guy. He really got me in a good spot."

"How are you feeling, Ben?" interjected an oblivious fan.

Crenshaw, nonplussed, was silent for a moment, then said, between clenched teeth, "Not too good right now." Thereafter, but for his chipping and putting brilliance, Crenshaw might have disappeared.

Then, at the 578-yard par-5 17th, Crenshaw finally made a birdie putt and, at the 18th, got perhaps the loudest ovation of the day when he chipped in for a birdie from 10 yards short of the green. From a similar, but much easier spot minutes before, Nicklaus had fluffed a shot, moving the ball only six feet and finished his fruitless day with a bogey.

Interestingly, both Sutton and Crenshaw have admitted to basic swing flaws which are bedeviling them. Crenshaw's driver has a mind of its own with definite leftward leanings, while Sutton never knows when he's going to block a shot dead right into the Kikuyu grass.

Almost all Sutton's problems were identical, the same sort of right-to-right blocked shots that bedeviled him at Williamsburg. His tee shot at No. 1 landed under a tree amid a knee-high pile of empty soda cans. After playing garbage man and removing the refuse, he chipped back to the fairway and made bogey.

That bad beginning could easily have led to disaster except for an amazing and lucky recovery shot at legendarily tough No. 2, which Sutton called, "probably the best up and down I have ever made in my life." Sutton's wild second shot stopped on a steep hill beside the green; his "impossible" pitch was the equivalent of a man on a third-floor porch trying to flip the ball onto a green 20 feet below him, but only 30 feet away.

The best he could hope was a 20-foot comeback putt for par, and, considering his lousy lie, a double bogey was possible. Sutton's fluffy wedge hit on the downslope, smacked into the pin and, instead of running 20 feet past, stopped four feet away, from where he made par.

Sutton's concentration was so great that he didn't notice the rumpled little man in the crowd who was no more than arm's length away when he performed his miracle, actor Peter Falk.

"What a wonderful shot, just wonderful," said Falk. "I'd love to ask him how he did it." Excuse me, sir, could I ask you just one more question about that wedge?

If Sutton wins this PGA by a single shot, Columbo may already have found the murder weapon.