When an indigenous black bear emerges from the undergrowth, as it did by the seventh fairway in yesterday's final round of the 107th US Open at Oakmont, startling tournament referee John Parmour before scurrying back to the safety of neighbouring trees, you just know that it is time to expect the unexpected.
So it proved to be, the season's second major providing a series of twists and turns that wasn't resolved until the very final pairing when Tiger Woods just came up short in his attempt for a 13th major, finishing - along with Jim Furyk - one stroke adrift of Argentina's Angel Cabrera.
On a day when the sun baked the greens to the extent that they caused misery to some of the world's greatest players, Cabrera - a gentle brute of a man who refused to be intimidated by either the course, or the challenge that included world number one Woods - claimed a maiden major victory, firing 69 for an impressive final total of 285, five-over.
It was an extraordinary final round; a supreme test of every player's fortitude, with Woods - who had a double-bogey on the third - and Furyk chasing Cabrera to the end. It was, ultimately, to prove a vain pursuit.
Aaron Baddeley, the Australian who carried a two-shot overnight lead, but paired in the final grouping with Woods, threw it all away on the very first green with a heavy-handed triple-bogey when he three-putted from four feet. It set the trend for an exhilarating contest, featuring a claustrophobic leaderboard that changed with regularity until Cabrera finally escaped the logjam and put his grip, loosely, on proceedings.
Cabrera - the first Argentinian to win a major since Robert de Vincenzo won the 1967 British Open - had moved clear with birdies on the 11th and 15th but then had to withstand a late charge from Furyk, the 2001 champion, and Woods before collecting the win of his career.
The 37-year-old former caddie, whose last win came in the 2005 BMW PGA at Wentworth, recovered from those late bogeys to set the clubhouse target with a par on the last and watched as his two chief rivals failed to find the birdie there that they required.
But his two pursuers had made life difficult. Furyk reeled off a hat-trick of birdies from the 13th which, combined with Cabrera - who got to three-under on his round with a birdie on the 15th - finally showing a human face by dropping shots on the 16th and 17th, put the pair tied at five-over.
Cabrera three-putted from off the front of the 16th green, and then, after deciding to lay-up on the 17th (where the tee had been moved forward to shorten the hole to 305 yards), he missed the green with his approach.
But Furyk too slipped up on the par four 17th when, after opting to attempt to drive the green, he pulled his shot into heavy rough. And, then, in attempting a deft chip, he left the ball in the rough. He ran up a bogey five and, with that, his challenge effectively came to an end. The chase ultimately was left to Woods, in the last group. But Woods, using a three-wood off the tee that left him in a greenside bunker, failed to birdie the 17th.
Niclas Fasth, with David McNeilly on the bag, finished as leading European. The Swede shot a closing round 70 for 287, seven-over, that left him alone in fourth place. Justin Rose and Paul Casey finished in tied-11th.
On a course that Lee Westwood described simply as "brutal"; which former champion Michael Campbell said had been set-up "to embarrass players"; that defending champion Geoff Ogilvy remarked of the last three days of his reign as "not much fun," Graeme McDowell finished with a 77 for 297, 17-over, to finish in tied-30th, giving him his best result in a major in America. His tied-11th finish in the 2005 British Open at St Andrews remains his best ever in a major. "It was a disappointing weekend," said McDowell. "I didn't feel great, energy-wise. Maybe it's the result of playing five (tournaments) in a row. These weeks are marathons, and you have to pace yourself. I'm glad it's over, though."