Sooner or later, Craig Stadler knew, something good had to happen.

Or at least the strapping chap with the Popeye forearms, the red walrus mustache and the droopy pants certainly hoped it would.

He'd hate to spend the whole third round of the Kemper Open at Congressional hitting the golf ball dead at the flag, dropping it down the stack and dancing it on the pin better than he ever had before in his life, and end up with nothing to show for it.

Finally, at the 554-yard 15th, Stadler's sky-high pitching wedge shot landed six inches from the hole, burned the cup on the way past, lipped again spinning back, and stopped on the edge for a tap-in birdie as the crowd roared.

The jinx was broken. Faster than you could say birdie-birdie-birdie, Stadler slammed a four-iron shot at the 211-yard 16th hole that missed the stick by inches and stopped 12 feet behind the hole, then followed with another wedge that stopped a yard below the cup at the 411-yard 17th. Both times, Stadler ran his putts into the heart of the cup.

"Right now, I feel like I can knock it in the hole from anywhere, and I damn near did, twice," Stadler said after his fast finish gave him a four-under-par 66 for yesterday's lowest round, an eight-under-par 202 total for three days and a two-shot lead over Tom Weiskopf (68) and John Cook (67) entering today's last lap of the chase for a $72,000 first prize.

Also in the hunt are Jim Simons (70-206) and the Edwards brothers, Dan (73-207) and Dave (68-207), who began the third round in first and 13th places, respectively, only to meet at sundown in a fifth-place tie. That will put the brothers together in the next-to-last threesome today.

For those who dream of come-from-behind thrills, classy Tom Kite (68) is tied with Beau Baugh (69) at 208, while Tom Watson (69) and Hale Irwin (70) could be construed to be in contention seven shots behind at 209.

However, anybody who saw Stadler yesterday, then listened to him later, got the impression that ony the two fellows who are within two shots of him have much chance of preventing the 208-pound strongman from improving on his second-place finish here last year.

"That's the best 18 holes I've ever played on (the PGA) tour," said Stadler, who won $206,291 last season. "Every time I pulled out an iron, I hit it anywhere from two inches from the hole to 12 feet, at the most.

"When I was only one under after 14 holes, I was afraid I was going to waste it all," he said, having earlier lipped out birdie putts of four and five feet as well as leaving two longer attempts on the edge. "I've been playing so good, I haven't dared hit a practice ball all week and I'm not going to start now. I don't plan on playing any different on Sunday."

This was the round the Kemper hit its stride. The crowd of 22,000 on a hot, windless day had a continual choice of delights

Cook made the most spectacular dash, with five consecutive birdies starting at the seventh, to shoot into a short-lived two-shot lead. The 23-year-old's streak started conventionally, then got spooky as, he admitted, "I got kind of magical. I thought I couldn't do anything wrong."

A four-iron shot to within two feet of the pin on the 166-yard seventh hole got Cook's motor running. At the eighth and ninth, he wedged shots into customary birdie range. Then, at the merciless 460-yard, par-4 10th hole, a monster Kite calls "that nice little par-5 up the hill," Cook unsheathed a two-iron, laced the ball 211 yards up the slope and left it eight inches from the hole.

After that, anything was possible. From the back fringe at the 11th, 30 feet from the hole and facing a scary downhill chip from a thin lie, Cook knocked his ball into the hole. The dimpled darling banged into the stick twice it was going so quickly, then drove into the cup.

"After that one rattled and dropped, I was going so good I didn't know how to feel," cook said. On the next hole, he was in the greenside weeds again. "And I darn near sank that one, too," he said.

This was a day of brilliant and bizarre spectacles. Watson ruined a six-birdie round with a four-putt double bogey at the ninth; George Cadle made back-to-back birdies while putting with a wedge after he leaned on his putter and bent the shaft.

However, Weiskopf, playing in the last group, provided the birdie coup de grace . The classic swinger, who drove like a muscle-bound hacker all day, pull-hooked his drive into dire jail at the 18th, then rocketed a nine-iron shot over a tree and onto the infamous pennisula green, the ball stopping in 60-foot, three-put range.

"And then," said Weiskopf, who was saved by his putter all day, "I sank it."

If this round offered blow-by-blow excellence, with Stadler, Weiskopf and Cook all tied at six-under before Stadler made his last two birdies to pull ahead, then today's is even richer in potential.

Perhaps no aspect of golf is so interesting as the changing internal chemistry of a player as he endures the final round.The greatest golfers meet this pressure with a self-sufficency that almost seems contrary to the spirit of the dastardly game. Watson, for instance, says he plays in his own private "rubber room."

Stadler, Weiskopf and Cook don't own one key to one rubber room among the three of them. A final threesome could hardly be imagined that would contain more tinderbox possibilities. Stadler and Weiskopf are among the all-time temper cases while Cook says, "I still haven't learned to play well in final rounds. I get too excited."

Stadler, who once sat in the azaleas at the Masters and cried from frustration, says, "I've never been able to hold much of anything in. I get in great hot streaks, but I also have periods of two-months when I'm in the pits. I have weeks when I'm so moody that I'm no fun to be around. I know I'm just going to be a pain in the rear . . . my wife goes home real quick, my caddie won't speak to me."

Just last week, Stadler went from radiant high spirits, and a four-shot lead in the Memorial Tournament, to the depths with consecutive double bogeys.

With age, Weiskopf, who has won only two tournaments in six years and who wants desperately to win his fourth Kemper to get a Masters exemption, is trying to present a mild-mannered image. Nonetheless, this master of self-destruction with the egg-shell concentration still looks at every airplane as though it were a personal enemy; the click of a photographer's camera in an adjacent county offends him like small arms fire.

"I took Woody Hayes' course when I was at Ohio State. You know, Photography 401," Weiskopf said, referring to the dean of all photog punchers.

For Stadler, who wears every emotion on his fiery face, for Cook, who still has to learn to cope with the furnance of a final round, and for Weiskopf, who wants a win more than could be good for any man, today will be a severe and public testing.