Jack Nicklaus, who has found his second golfing life at age 40, took command of the 62nd PGA tournament today with one of the hottest streaks in the history of the major championships.

Nicklaus had threatened to make Sunday's final round a mere stroll to his coronation. And even after bogeying two of the final four holes he still shot a four-under-par 66 for a 54-hole total of 205, three better than Lon Hinkle (70-69-69), the only other competitor at par or better.

Walking up the incline to the 12th green, one spectator in the crowd of 32,700 at Oak Hill Country Club's East Course yelled at the Ohio State alumnus, "The Buckeyes were never this hot."

A couple minutes later, Nicklaus missed a 17-foot birdie putt, "I was stunned," he would say later. When he birdied the next hole, a difficult 596-yarder, with a curling sidehill six-footer, he led the field by seven strokes. At this point, Nicklaus had seven birdies for the day and had missed two other opportunities inside three feet.

Nicklaus was so hot on this breezy day that, when he finally erred, it affected his game dramatically. He was fortunate to survive the final four holes with just two bogeys. He saved part out of a bunker at 16 and out of the trees at 18, on two of Oak Hill's most difficult par-4s.

I sorta thought the golf course ended at 14," Nicklaus said after the tournament's best round put him in excellent shape to become the first person since Ben Hogan in 1948 to win the U.S. Open and PGA titles the same year. "I was ready to come in, but they made me play the final four holes."

Actually, it was three putts on the treacherous par-3 15th that undid Nicklaus.

You get yourself on a run . . . birdying everything, and usually you don't even have to think when you're doing that," he said. "You're thinking but you're only thinking one thing -- Let's hurry and get to the green so I can get my next birdie and write down 3 on the card.'

That's what you think: Just keep on going. Then, all of a sudden at 15, I had to write down bogey and then all of a sudden, you back off and you think. And you get yourself in trouble. I was fortunate to wind up with 4 at 16 after all the things that happened. I should have kept things going."

At 16, Nicklaus twice averted disaster. His drive hit a retaining fence, in effect saving a two-stroke penalty. The closest he could come to the green was a bunker in front. Faced with still risking double bogey, he played safe instead of trying to get close. He then dropped a 15-footer.

When he made an uphill seven-footer on the final hole, Nicklaus had his 18th one-putt green over the two days. One was a 50-foot birdie on the first hole today that got him off to a roaring start from a gallery that climbed trees to watch his shots.

As he walked to the next tee, he smiled and said, "I'd like to break those into five-footers."

From there to the 14th green, Nicklaus missed as many three-foot putts (at 2 and 8) as he struck less-than-perfect shots.

At No. 5, which he has bogeyed each day, he tried to cut his tee shot on the 419-yard dogleg. But he pulled the ball and it ricocheted off a tall oak tree into the woods behind the fourth green. Off long grass flattened by spectators he had to hit his recovery shot between two pine trees four paces apart.

The perfectly struck three-iron shot landed in a fairway bunker. "i misjudged where the fairway was," Nicklaus said, "I used the wrong tree." But he took an eight-iron and left himself a routine two-putt for bogey from 22 feet below the hole.

After two-putting from 20 feet on the fringe at No. 6, Nicklaus birdied five of the next seven holes, lipping out from about two feet at No. - and missing the putt that stunned him at 12. His birdies came from 20 feet at No. 7, 18 feet at No. 9, eight feet at No. 10, five feet at No. 11 and six feet at No. 13.

That left Hinkle seven strokes behind at even par for a tournament many of the competitors had predicted would be won with an over-par total for the 72 holes.

"I remember thinking on the 14th green -- I was one over for the day, Jack was six under -- and I was thinking, "Gosh, I feel like I'm shooting 80,'" Hinkle said. "He was definitely in a different world for the first 14 holes."

Actually, some of Hinkle's errant drives and iron shots, which have given him trouble all week, left him with every opportunity to shoot 80. But his muscle enabled him to scramble for pars -- and even a tap-in birdie -- much the way Nicklaus' putting had saved him Friday when he one-putted nine times to add a one-under 69 to his opening 70.

The deep rough just off the fairways here makes strength a valuable asset. At No. 17 today, Hinkle showed why. He was 200 yards from the pin, 180 from the front of the green. The least-lofted club he could safely use to get out of the rough was a six-iron.

"I thought it was going to go in the (front) bunker," Hinkle said later.

But the shot carried the bunker and landed in the tall rough, losing enough momentum that it trickled to a stop six inches past the pin. It was his only short putt in making four birdies.

He canned birdie putts of 20 feet, after a short wedge approach at No. 4, and of 30 feet after a pushed six-iron at No. 6. He chipped in with a six-iron from 22 feet at the 15th, improving a shot after his ball lodged between the fringe and the rough.

Four times Hinkle's big drives left him with eight- or nine-iron shots that he flubbed to par-45. Two other bad shots cost him bogeys. He also bogeyed the par-5 13th, a victim of trying to compete against Nicklaus instead of the golf course.

That may have been because of the swings that occurred between these two players, who were tied at 139, one stroke behind Gil Morgan, going into today's play. Morgan lost two strokes to par in the first three holes and ended a one-hole charge by double-bogeying the par-3 sixth, where he hit his shot in the creek to the left of the green.

Morgan then made 12 straight pars for 73 -- 211, tying him with Andy Bean (68) for third place. The only other players within nine strokes of Nicklaus are Terry Dieht (68 -- 212). Curtis Strange (72 -- 212), Howard Twitty (71 -- 213) and Bill Rogers (72 -- 214).

Sunday, it will be unlikely that the winner will be anybody other than Nicklaus or Hinkle. so the final threesome, which will include Bean, amounts to match play between Nicklaus and Hinkle.

Today, Hinkle said, he realized playing Nicklaus instead of the course had hurt his game.

"I tried to play with Jack," he said. "I was three down after six, then I was about six down after 12 and I thought, 'Bluuuuh.' That made me rush a shot and cost me bogey at the 13th and I felt mad at myself."

Nicklaus harbored no such thoughts.

"There were some swings, weren't there?" he said. "but I just kept playing. I don't pay any attention to it until we get to the last nine holes."

So golf's all-time money winner at $3.5 million, who had not won a tour- tournament since 1978 or a major since 1975 until he won the U.S. Open at Baltusrol in June, now smells his fifth PGA Championship, which would tie him with Walter Hagen.

He promises no letup Sunday, only a continuation of his aggressive game. "If you wait for somebody to catch you," Nicklaus said, "somebody will."