|Ryder Cup 2016|
|Venue: Hazeltine National, Minnesota Dates: 30 September-2 October|
|Coverage: Live commentary on BBC Radio 5 live, highlights on BBC Two plus live text commentary on the BBC Sport website. Details.|
If you were wondering how partisan and aggressive a sedate game like golf can really get, it is worth considering that, when two autumnal leaves descended gently onto the unguarded second green on Friday morning, their swift removal by a groundsman wielding a leaf-blower was greeted by chants of "USA! USA!"
Nature nil, Nationalism one. When even a leaf gets a hard time for stepping on American soil, you know Europe's golfers are in for a whole heap of headaches.
So it was on the opening morning of this 41st Ryder Cup, a day that began with thousands of home supporters stampeding through the Minnesotan pre-dawn to grab the most favourable viewing spots and ended with Darren Clarke's men making a spectacular charge of their own for the high ground.
At midday, USA having won all four of the morning's foursomes in all possible manners - with easy dominance, from behind, with cool control, with a magnificent late assault - it was shaping up as the Hammering at Hazeltine, the long, sun-kissed course a raucous Minnesotan knees-up, the tourists wilting under a beery torrent of one-sided support and blunt-edged wit.
Four hours later, Europe having stormed the fourballs 3-1, each of the victories a thumping, it was instead Hang About, Hazeltine - an overnight lead for Davis Love's men of just 5-3, memories surely stirring in the skipper's mind of Medinah four years ago and a last-day turnaround that gets more miraculous every time you think of it.
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That a crowd who came to party ended the day silenced and streaming early out of the exits was all the more remarkable for the atmosphere created throughout the first part of the day.
Henrik Stenson and Justin Rose, up against Jordan Spieth and Patrick Reed, were the first to experience it and the first to stagger under its weight. On the sixth, Stenson's approach found a greenside bunker. "Suck it!" bellowed a delighted chap dressed as Abraham Lincoln, his costume perhaps more historically accurate than his language.
Reed was a man brave enough to march into that chill, misty morning in shirtsleeves when all around were jumpered and wearing bobble hats, a competitor feisty enough to walk into the bear-pit of the first tee and cup his hand to his ear as if the relentless chants were failing to get through.
Reed is not cut like an athlete. One of the reasons he could get away with short sleeves is his generous layer of natural padding. But he is built for the confrontations of this special competition, revved up by a fan of similar girth yelling, "I like that, baby!" as his clubhead made contact with one pressure chip, refusing to concede a two-foot putt to Stenson on the ninth despite getting the daggers from Rose.
On the same hole, Rose's approach had been greeted with a shout of "get in the water!" There is no water on the ninth, but in the giddy, febrile atmosphere the Ryder Cup produces, the quip went down with the packed galleries like free beer.
Shortly after the American pair had sealed their 3&2 win in the amphitheatre of the 16th green with high-fives so fierce they sounded like whips being cracked, Reed was driven through the adoring crowds on the back of golf buggy like a corpulent emperor returning from a glorious battle on his shield.
If that result was no surprise, the US having led from the second, Zach Johnson and Jimmy Walker were midway through an astonishing run of five successive hole wins to beat Sergio Garcia and Martin Kaymer 4&2, while Phil Mickelson - unable to find a fairway from the tee all round - and his partner Rickie Fowler then came from two shots down with four to play to burgle Rory McIlroy and Andy Sullivan 2&1.
"Sweeeep!" roared the crowds, 30-deep along some fairways, 50 deep on the banks around the greens. There were men dressed as bald eagles, squadrons of Uncle Sams, at least three human Statues of Liberty. The only home spectators not carrying the small Stars and Stripes given out free at the gates were those holding large Stars and Stripes.
Not since 1975 had the US led 4-0 after the first session, one of the two years when the side was captained by Arnold Palmer, whose old golf bag had been placed on the first tee and whose recent departure hangs over this year's contest as did Seve Ballesteros' at Medinah.
A European team has been behind in the first session of the past four Ryder Cups and won three of them, but never before has a team behind by three or more after the first morning ever come back to win.
When Reed and Spieth went one up on the second in their fourballs rematch with Stenson and Rose and Danny Willett - booed vigorously on the first tee either in protest at his brother's comments about US fans or to prove them - soon fell behind with Martin Kaymer against Brandt Snedeker and Brooks Koepka, it became harder still for the isolated pockets of doughty European support.
And then, slowly at first but with dramatic acceleration over the front nine, it began to change.
Stenson began dropping putts. Garcia and compatriot Rafa Cabrera-Bello, family friends, Olympic team-mates, put JB Holmes and Ryan Moore under a Spanish inquisition.
Belgian rookie Thomas Pieters had played steadily enough in his morning foursome with Lee Westwood but been let down by his experienced partner's disappointing form. If Pieters and Lee had been out of tune, the afternoon's duet with McIlroy was a sweeter thing altogether.
By the seventh they were four up on Dustin Johnson and Matt Kuchar, two holes ahead of them Garcia and Cabrera-Bello four up too at the turn.
It sucked the air from American lungs and put backsides back on seats when before it had been all jumping around and standing room only.
There was still a fierceness in the shouts - a missed birdie attempt from Rose at the lakeside 10th triggered cheers, a Stenson backswing on the same hole featured a "miss it!" - but the earlier triumphalism had gone. Reed went fast from pumped to pooped. Moore, Love's late last wildcard, wore the responsibility heavily.
When McIlroy sealed his and Pieters' 3&2 win with a nerveless eagle putt from 15 skiddy feet on the 16th, he held his arms out wide to the thousands all around and then bowed with mock servility. Game over, game on.
Clarke has decorated the European team room with inspirational images and quotes. One of the most prominent, painted in yellow script high on the blue walls, is an abbreviated version of a Winston Churchill standard.
"Never give in - never, never, never, never."
Europe are still down. But they are on the way back up.
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