Rory McIlroy remains in contention for US PGA behind leader Brooks Koepka

As Bryson DeChambeau was subjected to boos, Rory McIlroy rolled back the years and brought on the cheers. McIlroy’s demeanour after a first round of 71 at this US PGA Championship was so downbeat that the prospect of him claiming the Wanamaker Trophy for a third time felt about as likely as him signing up for LIV Golf. How easy it was to forget that nobody at the summit of this sport can flick their switch like Rory McIlroy.

This was a curious major afternoon. Oak Hill turned into Soak Hill as rain battered upstate New York. DeChambeau, one of LIV’s poster boys, was audibly heckled as he took to the first tee alongside fellow rebel Brooks Koepka. Crowds in this part of the United States are not known for their restraint but this was still a departure from the general atmosphere.

Day four could be interesting; DeChambeau very much remains in the US PGA hunt. Koepka, seeking to atone for his heartbreak at last month’s Masters, heads the field at six under par. Koepka has backed up a 72 with two 66s. Viktor Hovland and Corey Conners share second at minus five, two clear of DeChambeau.

On the gallery reception, the LIV player said: “I don’t care. I mean, it’s not a big deal. Look, it’s New York and I expect it here. I appreciate the fans. Them doing that to me, it’s like, OK, cool, no problem. I’ve got no problem either way. If we got applause, that’s fantastic and if not, you know, whatever - it is what it is.”

McIlroy wants to focus on his work inside the ropes rather than his leading role against the LIV threat. This is fair enough; golf and McIlroy mutually benefit when the Northern Irishman is at his best. The 34-year-old, who missed the cut at both the Players Championship and the Masters, was battling technical demons earlier in this major week.

Those flaws looked like haunting McIlroy again as he dropped shots at the 6th, 8th and 9th to counteract birdies at the 3rd and 5th. The response was of a man who believes he can end a wait for a fifth major which stretches back to this tournament in 2014. McIlroy birdied the 12th, 13th and 16th. He bravely saved par after missing the green at the par three 15th.

The penultimate hole brought an aberration after McIlroy overshot the green from a fairway bunker, but rescued a four at the last despite his tee shot leaking into right rough. McIlroy signed for a 69, his second in as many rounds, which leaves him one under par on aggregate. More interesting than the look of his scorecard was the smile back upon his face. He senses opportunity.

“If you had have told me on Thursday night that I’d be going into Sunday with a realistic chance to win this golf tournament, I would have taken it,” said McIlroy. “I still don’t feel like my game is in great shape. I’ve held it together well. I’ve holed some good putts. I’ve scored well.

“I probably hit it a little better off the tee today than I did the first couple of days but I think at this tournament and especially in these conditions on this golf course, the non-physical parts of the game are way more important than the physical parts of the game. I think I’ve done those well and that’s the reason that I’m in a decent position.”

So too is Justin Rose. The resurgent Englishman’s 69 moved him to two under. A second major win, a decade on from number one, is feasible. Rose has Scottie Scheffler for 54-hole scoring company after the latter slipped to a 73.

Tommy Fleetwood marched through the field courtesy of a 68, posted in the worst of the day’s conditions. He now sits inside the top 10 at one over. “I am unbelievably pleased,” said Fleetwood.

“It was just relentless really from the start of the warmup to literally as we were putting out on the last green. There was very little wind but that doesn’t stop it playing cold and long and wet.”

A wild morning at the office for Padraig Harrington saw the 2008 champion play the front nine in 43 and recover by 11 shots after the turn. “I was just trying to break 80,” said the Irishman of his thoughts when heading to the 10th tee. “On a normal day I would have played the front nine in two over and would have been moaning about it.

“I three-putted the first two greens. On a tough day, you need momentum. I three-putted the first two greens then hit it over the back the next, so I threw away three shots straight away. And the same on seven, eight, nine. I’m on the fringe three times and I made three bogeys. I had eight fives on that front nine.”

Unlike DeChambeau, LIV’s Phil Mickelson received a warm ovation as he stepped on the opening tee at the third round of a major for the 100th time. “Playing in these tournaments is something I’m very appreciative of,” said Mickelson after his 75. “I mean, it just shows how old I am, I guess, and how many years I’ve been playing. But it’s been really fun to participate in so many great events and play well in them.”

Mickelson’s ultimate glory in this event came two years ago, at the age of 50. McIlroy is suddenly summoning the spirit of his 20s.