He waited until the ambulance parked next to the first-aid tent. He took a deep breath and let his shoulders fall loosely. He needed a drive in the fairway on the 18th hold. No time for another sideways tee shot. Not now. He needed a par at the 18th. He needed it not for the money, not for fame. He needed it to keep on living.

Jeff Thomsen is the 217th-leading money winner on the pro golf tour. Long division tells us that Tom Watson is making $95.40 per shot this season. Jeff Thomsen is making 32 cents a shot. As the Cabin John Volunteer Fire Department ambulence clattered by on a stone roadway 10 yards from the 18th tee, Thomsen waited for silence. "This," he thought "is crucial. Get ready."

Watson is in hot pursuit of immortality. He came to the Kemper Open at Congressional Country Club only to warm up for the U.S. Open two weeks later. Another $30,000 is nice, and the first prize of $72,000 is nicer yet, but with $346,125 already in the bank this year, Tom Watson doesn't care about money.

Neither does Jeff Thomsen, who has won $375 this year. Money is important to Thomsen only in that it is the measuring stick by which the PGA Tour separates the prospects from the suspects. At 26, Thomsen is a first-year tour player; as such, he must win $8,000 in a year to keep his player's card. Anything less, he must go back to the PGA qualifying school and prove anew his ability.

He needs to earn $969 this week in the Kemper.

Or else.

If he's short on the $969, he can go to Atlanta next week and try to earn the rest of his $8,000. But that would be a daring gamble, because he would would have to skip the PGA school which is the same week. He would have to wait six months if he needed to try the school again. The best thing, then, is to make the $969 right now.

Or else, the life he wants is over.

Or else it has been for nothing -- the four years at Arizona State, the two years playing in Japan and Australia and Europe, the dreary days of minitours that cost him $600 entry fees, the four maddening times it took to make it through the PGA Tour qualifying tournament -- all this pain and work for nothing.

Win $969 or else. Or else he goes back to that livf. Being the 217th-leading money winner on tour isn't much, but Jeff Thomsen knows this: it's better than not being on tour at all. In their first year, some men who became big-money winners started slowly: Andy Bean 139th in money, Tom Purtzer 194th, Craig Stadlelr 196th.

So while a Tom Watson chases everlasting glory, a Jeff Thomsen can come to the 18th tee on the second day of just another weekly tournament, needing a par to qualify for the last 36 holes and keep alive his chances of making that sweet salvation $969. And who is to say where the most pressure lies: on Watson, who has tasted fame and loves it, or on Thomsen, who works in the candy store but isn't allowed to sample the good stuff?

That $969 would put Thomsen over the required $8,000 mark in earnings for the calendar year since he made it through the PGA school. It would keep him on tour another six months at least, with the next step being $8,000 in earnings for the 1980 season.

After a 75 the first day, it seemed plain yesterday morning that Thomsen would need a 73 to be one of the low 70-and-ties who would play the final 36 holes this weekend. There were 156 players at the start.

Thomsen came to the 18th tee needing a par for his 73 and a 148 total.

You would like Jeff Thomsen. He's a Gary Player look-alike, a smallish compact man with sharp features and wide-set brown eyes. He's 26 years old, a bachelor, the son of a municipal golf pro from Twin Falls, Idaho. As Thomsen came off the ninth green yesterday, sailing along on the wings of a 35-foot birdie putt, a spectator said to him, "You got it in you." And Thomsen said, "I know I do." He marched to the 10th tee directly.

The game was on. What might have been a disastrous front nine had been saved by that long birdie putt, a putt "I knew was good all the way because I just had the feeling." After a bogey at the 10th, Thomsen again rolled in a long putt, this one a 30-footer that broke six feet from right to left on the 12th green. His smile was measured in megawatts.

He hurried too much. He didn't get set for the drive at 13. He pushed it far, far right into the woods. He could see an opening. He might gamble. He has before. Go for it? Hit it under one tree and over that one 150 yards away? 'He could make par that way. He needed a par. He was already seven over. Another bogey and he might be off the tour forever.

'"The difference between the $100,000 players and guys like me is that they don't make the dumb double bogey's," Thomsen would say later. "You have to learn when to make a smart bogey."

From jail at 13, Thomsen chipped back to the fairway and made his smart bogey. Now, eight over par. On the edge. Eight over, 148, probably would make it, but might not. If Watson doesn't make a par, he might win $45,000 instead of $72,000; if Thomsen doesn't make a par, he may never get to make another swing on the PGA Tour.

At the 14th, with a simple eight-iron shot to the elevated green, Thomsen hit it too far. It left him an impossible chip from a monster hump behind the green. "I should have choked down on a seven-iron and run it up there," Thomsen said. "A mental error. You don't want to go through that green. Such a fine line out here. Such a fine line between being a top-money-winner and being a guy hanging on by his fingernails. It's making the right decision."

Now, Thomsen was nine over par. 149 might make it, but probably not. The last four holes of any tournament test a man. Johnny Miller once walked down the 15th fairway at Augusta thinking of how he'd look in the green jacket; the last four holes took him out of that jacket. With four holes to play yesterday, Jeff Thomsen had his own little Masters at hand.

His gallery was nervous. Her name was Margaret Bell. Thomsen is staying this week at her parents' home. The year has cost him $25,000 already and it's nice to save a buck here and there. "He'll make it," the gallery said with a smile. "He's a Christian."

Moving the ball back in his stance for drives -- "Anytime I'm wild left and right, the ball is up too far" -- Thomsen hit perfect tee shots at 15, 16 and 17. A Christian who can putt like the devil is quick to take advantage of perfect placement, and after two pars Thomsen trickled in an 18-foot down-hiller for a birdie at the 17th.

"Relief," he thought, "I'm in."

The ambulance parked. Thomsen stood up to the crucial drive at 18. He had begged his way into the tournament by telling his story to Billy Booe, the tournament director, who decided it would be "a nice thing" to give a precious sponsor's exemption to a struggling rookie. Without such an exemption, which usually goes to local heroes or fading stars, Thomsen would have had to play in a Monday qualifier for the Kemper.

As Thomsen's last drive descended, his playing partner, Larry Ringer, the club pro at the Naval Academy Golf Course, talked to the distant Titleist, "Bounce hard left, darling."

It did, turning toward the center of the fairway.

"One more time, darling," urged Ringer.

It bounced left again.

Ringer then shook the hand of a man who won his own little Masters on the second day of just another tournament. Jeff Thomsen breathed deeply and said thinks. Ten minutes later, he made the par 4 for his 73 and a 148 total.

The 149s didn't make it. "I've got my $1,000 now," Thomsen said. "Last-place money is $800. And I'm nt going to finish last." He needs to finish 51st -- of 82 players -- to win more than $969.