Rory McIlroy's PGA Championship week has been packed with self-deprecation. But with his opening-round woes now firmly behind him, it's time to make a serious push for major number five

“That’s when daddy was good!” It was a beautiful moment between Rory McIlroy and daughter Poppy as he showed the one-year-old a mural celebrating his two PGA Championship victories.

The second of those was his last major victory. Even after all these years, that statistic feels so unlikely it needs double checking every time.

While Poppy won’t appreciate the self-deprecation just yet, she will understand her dad’s beaming smile if the week ends in him hoisting the giant Wanamaker Trophy into the Oklahoma skies on Sunday.

McIlroy’s first-round woes since he edged out Phil Mickelson in the dark at Valhalla are well documented. In case you need reminding, before Thursday he was 35-over-par for the first 18 holes at majors. For rounds two to four, he’s a combined 68-under.

Buoyed by his draw with Tiger Woods and the Grand Slam-chasing Jordan Spieth – “It’s a pretty comfortable group for all of us, we’ve all played together a lot and we all know each other pretty well” – McIlroy didn’t waste any time in banishing his first-round demons.

Starting on the back nine – generally considered the more scorable half of the Southern Hills test – McIlroy exploded into life on his third hole with a 354-yard bomb, an 86-yard flick, and a kick-in birdie.

“It was my perfect number,” he explained. “It was nice to take advantage of such a good drive.”

It kick-started a run of four straight birdies. The last time McIlroy holed four birdies in a row at a major? The 2014 PGA Championship. And we all know what happened there.

By the time he’d reached the par-5 5th, his 14th hole, the Northern Irishman added two more birdies to reach 6-under and make the early few hours of this PGA Championship about as exciting as they could be.

But this is McIlroy we’re talking about, who likes to keep things interesting. So when he took eight shots to play the 6th and 8th – both par-3s – it was hardly a huge surprise. Certainly not in the long-term context, anyway.

And while the rest of the field will have been licking their lips as the huge leaderboards revealed the four-time major champion’s stutter, they’ll have been rolling their eyes not long after as McIlroy curled home an 18-footer for birdie on the 9th to close his round.

“That felt nice,” McIlroy told Sky Sports afterwards. “I have [felt comfortable] – and I’ve felt that way for the last few weeks.”

The birdie meant a 65 for McIlroy, his lowest opening round in a major since the 2011 US Open. And the last four times he opened with a 66 or better at a major, he won them all. “He made it look easy,” Woods, said afterwards.

“I’ll try not to get ahead of myself,” he said. It’s OK, the rest of the golf world will do that for you. “It’s great to get off to a good start at a major championship for a change.”

With an afternoon tee time on Friday, McIlroy now has plenty of time to relax and gather his thoughts.

And perhaps tell Poppy that her daddy is good again.