Trying to navigate Chambers Bay's lumpy, grumpy layout is more than enough to make a golfer queasy. But Jason Day's sickening moment here Friday went well beyond deep bunkers and lightning greens.
The day had been going quite well for the 27-year-old Australian star, as one would expect.
He is one of those players who seems destined to win one of golf's majors. You just know it.
He hits it long. Putts it true. He swings the club as if he has an arc-control button he pushes that reads "smooth."
In 2011, at age 23, he finished second in the Masters and U.S. Open. In 2013, he was third in the Masters and second in the U.S. Open. Last year, in the crust and dust of Pinehurst No. 2, he was tied for fourth in the U.S. Open, albeit 10 shots behind winner Martin Kaymer.
He has played in 18 majors, withdrawing once, missing the cut twice and finishing in the top 10 seven times.
He is a man on the verge.
He got a fast start to this season by winning at Torrey Pines in a playoff. He had a history of injury and ailment, prompting his caddie, Colin Swatton, to tell Tod Leonard of the San Diego Union-Tribune that a year of good health was their goal.
"That's all we wanted," Swatton said, "... And this is the start."
He shot a two-under-par 68 in his opening round here Thursday, three shots from the leaders. He was one over for his round heading into the back nine Friday, his back nine starting with the par-five No. 1, which was a par-four Thursday and probably will be a par-five again Saturday.
Don't ask. This is the U.S. Golf Assn., playing with handcuffs and thumbscrews. Expect only pain.
Day's second shot into the green on No. 1 was long enough, but settled into a greenside bunker. He had about 15 yards of green between his shot and the pin, but if he hit it a tad too hard it could catch a hill and roll down a 30-foot hill.
He hit it a tad too hard.
He was now 40 yards away. ("That is a joke," he muttered). He needed to hit it hard enough to get it back up the hill, but not so hard that it would trickle back down into the same trap. Balls on the undulating greens at Chambers Bay always seem to wander about, seeking evil.
Day had the kind of shot that would prompt a 20-handicapper to either throw his bag into a lake or swallow his pride and try to putt it up the hill. It was also the kind of shot that can bring a triple bogey and an end to a player's title chances.
But how often we forget what they keep telling us. These guys are good.
Day swung, the ball lofted enough to make the green, bounced a couple of times and went right into the cup.
Day tossed his club in the air. On the green, where he had the closest look at the shot, Jordan Spieth threw his arms in the air.
"I screamed," Spieth said. "I was like somebody in the gallery. I probably wouldn't scream if he did that Sunday and we were tied."
Witnessing the shot from greenside, it was difficult not to think that moments like this, in a major, where a likely seven becomes a four, are those discussed later when that same player is holding the trophy.
That thought persisted when Day made a long birdie putt on the next hole.
So Day's positioning for title contention seemed in order as he walked toward his second shot on his last hole, the par-three ninth. He was three under, two off the lead, and was a good sand shot and a putt away from finishing the day that way.
And then he kind of crumpled on the side of a hill. He didn't slip or slide. He just kind of folded up and went to the ground.
History came flooding back to those who have followed Day. He has missed chunks of time on the tour with a series of health problems, such as swine flu, bronchitis, sleep disorders and sinus conditions, the latter requiring surgery. He also missed time with a left thumb injury.
But more serious were the times when he was forced to withdraw from events with bouts of dizziness.
Tiger Woods, in the group following Day, Spieth and Justin Rose, watched from afar.
"I know he didn't play in Dallas this year because of vertigo," Woods said afterward. "I played with him at Memorial and we talked about it in depth. He did a blood panel and all that stuff. I hope he is OK."
After going down, Day rolled on his back and his caddie, Swatton, hovered over him. As photographers swarmed in close, Spieth tried to shoo them away.
Slowly, after maybe four or five minutes, Day got to his feet, leaned on his club, went back to one knee and then slowly, shakily, made his way toward his ball. He had trouble getting down into the trap, looked unsteady over his ball, but somehow splashed it out close enough to two-putt and get helped away by medical personnel.
It was a gutsy finish. We probably won't know until Saturday if it was a tournament finish.
About four hours after it happened, the USGA released a statement that said doctors had diagnosed Day's incident as an attack of "benign positional vertigo." The statement said he was resting and hopeful of playing Saturday.
According to medical journals, there are many ways to treat vertigo. Playing Chambers Bay does not appear to be one of them.
Follow Bill Dwyre on Twitter @DwyreLATimes