Perhaps the soaring heat had something to do with it, as John Daly – proving as madcap as his loud clothing – threw a club into Lake Michigan and Eddie Pepperell, believing the magic had escaped from the wand, simply gave his putter away to a young spectator.

Against such acts of folly and benevolence in this 97th edition of the US PGA Championship, there were those who remained cool, calm and collected, which are the attributes most required in the real heat of competition, at least until play in the second round was prematurely halted due to inclement weather and the threat of lightning in the Kohler area.

When the siren sounded – just before 5.30pm local time with not a breath of wind but darkening, threatening clouds forming over the contrived lakeshore links – two Australians, Jason Day and Matt Jones, shared the on-course lead on nine-under-par, a stroke ahead of England's Justin Rose who was playing the 18th when called in.

Rory McIlroy, for his part, had backed up an opening 71 with another 71 for 142 to not only confirm his wellbeing after rehab on his ankle ligament rupture, but also that he had retained sufficient sharpness to contend.

With the cut expected to fall on two-over, it meant that Shane Lowry and Pádraig Harrington – both on 147, three-over – were destined to miss out on the weekend, while Graeme McDowell and Darren Clarke, on his 47th birthday, were also cast aside.

Top of the leaderboard

For the most part, those atop the leaderboard were from the half of the field given early tee times in the first round and late starts in the second.

David Lingmerth and Jordan Spieth were among the exceptions to the rule, having long completed their rounds when the weather front closed in.

Lingmerth has never won a Major – no male Swede ever has – but his progress in the sport has resembled a supped-up Koenigsegg supercar this season.

A breakthrough PGA Tour win in the Memorial tournament, where he beat Justin Rose in a play-off, has been followed by a sustained period of contending that has seen him have three top-10s in his last four outings.

In shooting a second round 70 to go with his opening 67, for seven-under-par 137, Lingmerth reached the midpoint of the championship with a growing sense of expectation.

“To get two solid rounds in the first two (days), it’s a good feeling . . . really, really happy with the way things are going so far,” admitted Lingmerth, who nevertheless continued the fine art of players rarely being entirely happy with their games by going to the range to work on his ball-striking.

Spieth rising

If Lingmerth – short in stature but big of heart – was an unlikely 36-hole clubhouse leader on a course where the bombers have a decided edge, there was also the rather more familiar presence of Spieth yet again rising to the challenge on golf’s biggest stage.

The 22-year-old Texan already has a green jacket from Augusta and a silver trophy from the US Open among his list of honours this stellar season, and his quest to add a third Major title this season was strengthened with a second round 67 for 138 that moved him to within a stroke of Lingmerth.

The one-two rivalry in the world rankings with Rory McIlroy has been a running sideshow – “Rory is ranked number one, so he is number one,” insisted Spieth, adding: “I think he, for the first two days back in competition after that long layoff, he seemed to swing very freely, no restrictions. It’s great to have him back. We get along great. That’s just a ranking system and obviously it’s a ranking system that I strive to be at the top of at some point.”

However, the real quest is for the Wanamaker Trophy.

Highlight shortcomings

And Spieth, as much as anyone, has seemed at home on a course which Darren Clarke observed, “will highlight any shortcomings in your game. If you miss it anywhere around here, you are going to pay a penalty.”

Except, in Spieth’s case, a holed-out bunker shot on the 18th for a birdie seemed to imply that the 22-year-old Texan was above such a penalty.

As the world number two observed afterwards, “We were thinking about playing 10 feet out to the right just given my back swing.

“It had to be almost straight up and straight down. And the chances of hitting that the right way are so slim you could easily catch that thin and then you’re left with a very likely double bogey. So I lined up a little to the right and as I took it back just tried to kind of cut across it a bit. I just struck it absolutely perfectly.”