Rory McIlroy pleased with recovery on day two of PGA Championship

McIlroy was heading for an early exit after dropping five shots in his first three holes of the day to limp to the turn in 40, but the four-time major winner produced a hat-trick of birdies from the fourth and picked up another shot on the eighth.

The resulting 71 left McIlroy on the early projected cut of three over and with the Black Course posing a daunting test, almost certainly safely through to the weekend.

"I just needed to see one putt to go in, to see something hit the bottom of the hole and that was on the fourth," the 30-year-old said. "From there I started to play some good golf.

"I had an horrendous start, five over after three, but came back well and the goal after those three holes was to be here for the weekend and it looks like I have done that, which is nice."

Asked what kept him going after slumping to seven over par for the tournament, McIlroy added: "Pride. Just pride. Just trying to play a good round of golf and try to get something that's close to the best out of myself.

"And I don't like missing cuts. It's not something that I'm used to fortunately and I wanted to be around for the weekend. At least if you're around for the weekend you can go out there and maybe shoot a good one and at least give yourself half a chance.

"I was four over through three in Boston a couple of years ago and ended up winning the tournament, and that just sort of came back into my mind after I made that start. So in a way it's calming.

"I've been in this position before and I've been able to come back. Or you go back to Birkdale (the 2017 Open) a couple of years ago where I was five over through six and shot 71 and ended up with half a chance on the back nine that week.

"So it's not as if I haven't been in those positions before, it's just a matter of not pressing too much and staying patient and letting the good golf sort of come through. Took a while today, but it eventually got here."

Spieth: Grand slam not on my mind

Jordan Spieth insisted he was not thinking about completing the career grand slam despite emerging from his slump at the ideal time.

Spieth needs to win the US PGA Championship to join Gene Sarazen, Ben Hogan, Gary Player, Jack Nicklaus and Tiger Woods in winning all four major titles, but was rated a 40/1 shot to achieve the feat this week after enduring a poor season.

However, the former world number one added a second round of 66 to his opening 69 to set the early clubhouse target on five under par, a shot ahead of world number one Dustin Johnson and compatriot Daniel Berger.

Asked if the prospect of joining golf's most elusive club had crept into his mind, Spieth said: "It certainly hasn't. I can't imagine it will because I haven't been in contention on a Sunday since The Open last year.

"If I'm able to put some good work in tomorrow, then I will be in contention on Sunday and at that point it will be just more (thinking) of trying to win a golf tournament. It won't matter to me what tournament it is.

"I'll be pleased to be in contention, knowing that the work I put in from being pretty far off has really come back nicely on a very difficult golf course. I imagine that will take pretty much most of my thought but we'll see. I'm not sure what to expect.

"I have to not be results-orientated and focus on progress. The ultimate goal for the week is to have a chance to win on the back nine on Sunday. This golf course makes you stay patient, you don't think ahead."

Spieth conceded at the start of the week that he "was in a bit of a slump" but carded six birdies and two bogeys in his 66 and feels close to the brilliant putting he was renowned for in winning the Masters and US Open in 2015 and missing out on a play-off for the Open by a single shot.

"I think I'm probably 90 per cent back to when I was at my best and the only difference maker is speed control," added Spieth, whose best finish this season is a tie for 21st in the Masters.

"Speed control has still been just a little bit iffy, but I'm as good or better. I feel as good or better 15 feet and in."