Rory McIlroy might feel he can perform a final round miracle with a closing 62 and challenge for the US PGA but his optimism about the final round came before Jordan Spieth closed in on Jason Day with a finish that suggests that he may well be world No 1 before Sunday is out.

The world No 1 was six shots behind clubhouse leader Branden Grace (64) on six under par shortly after he finished and rather than throw in the towel he took a question about the 62 he shot to win at Quail Hollow in 2010 and said: “I definitely believe it is out there for me. I feel I’m playing well enough to do shoot something like that.”

Trailing Day by nine and Spieth by seven—the Masters and US Open came home in 30 for a bogey free 65 that gives hm a shot at the probably win he needs to take over at world No 1—McIlroy’s biggest problem is not the gap on the leaders but the fact that he’s tied with six other players with another 16 ahead of him.

The six include Justin Thomas, the 22-year old phenomenon from Louisville, and his final round playing partner Charl Schwartzel.

Ahead, are some of the most exciting young names in the game and expecting all of them to have an average day is probably asking a lot.

“As long as I’m no more than ten shots back going into tomorrow, I feel with a great start again and trying to keep the momentum of the round going, there is no reason why I can go out and shoot 64 or 62 that I might need,” McIlroy said after a third round 68.

McIlroy really needed the 62 yesterday but having raced to four under after five, he had to birdie the 16th and 18th for his four under par round given that it was two steps forward and one step back for the rusty Co Down man in what was is his first tournament since June’s US Open.

He admitted he got ahead of himself at Whistling Straits where the scoring average for the Straits Course yesterday was 70.62 compared to 72.9 on Friday and 74.1 on day one.

A mid-round wobble stopped his charge but he still felt reasonably happy about his game and what remains for him this season after finishing on six under with an eagle and six birdies on his card.

McIlroy said: “I got off to a dream start, really. To be four-under through five and not having birdied the first and third was a bonus.

“But to give those shots away again on six and eight you really have to battle to shoot four-under in the end. 

“I guess that probably shows just a lack of competitiveness and considering this is the first week back in a few weeks.

"It was a day that started well and ended well, birdieing two of the last three holes. The stuff in between was a little patchy at times. 

“But I hit a lot of good shots, I putted better. There were just a couple of loose ones here and there. I came off the course definitely thinking there was a really low one there. 

“It’s still my best score of the week, but it could have been a lot better.”

McIlroy began the day on two under par, 10 strokes behind halfway leader Matt Jones of Australia, (who shot 73 to fall back to sixth on 10 under) and four behind Spieth.

He was always going to need a special round to get himself back into contention and after birdie at the par-five second and another fourth, he then drained a 20-yarder for an eagle three from just off the green at the fifth to join the yet-to-start Spieth in a tie for seventh on six under.

“That was a bonus,” he said of the eagle. “I told JP to leave the pin in and I'm glad I did, it was going six or eight feet past. 

“It was nice to see that one drop. As I said, dream start and a little disappointing that I wasn't able to keep it going from then.”

A birdie at the drivable sixth might have frightened a few but McIlroy, who had admitted during the week that his wedge play was a weakness, bunkered his blind 106-yard approach and missed a six footer for par.

Momentum is key and  a bogey at the 507-yard eighth, where he bunkered his tee shot and his approach, sent him tumbling back down the leaderboard at a moment when he needed even more impetus. 

It could never have been any other way after an enforced five week break spent wearing a surgical boot for the most part.

Asked if he might have been sharper had he played in Akron last week, he said: “I didn't want to play last week because I didn't want to jeopardise playing this week. 

“There's no point in playing last week and then it flaring up. And then you completely throw this tournament into question. 

“It could have made a difference, but again, my health's more important than the scores that I'm shooting out there.”
Dressed all in black, he hit back from the bogey at the sixth with a birdie from seven feet at the 10th, but he failed to birdie the par-five 11th after a pushed tee shot and then continued his rollercoaster adventure down the stretch.

A birdie from seven feet at the 13th was followed by a missed seven footer for birdie at the 14th and a bogey at the 15th, where he bunkered his approach

Still, he kept going and birdied the par-five 16th and then rolled in a 12 footer for another birdie at the last — a testament to his great competitive spirit.

“There are a few difficult holes out there but bogeying six was a big momentum stopper,” he admitted. “And then not getting that shot back straight away was tough, and then bogeying eight as well. 

“But I felt like I bounced back well on the back nine and got a couple under. If I can improve on that tomorrow it will be a good showing in what is my first week back in eight or nine weeks.

“I know that the way the back nine's playing there, the leaders could be 14-, 15-under by the time the day ends. So, that would leave me eight shots back. 

“In the back of your mind, you still think you have a chance, because that's what your competitive nature tells you. 

“But if you're looking at it realistically, I want to go out there tomorrow and shoot the best score that I've shot this week.”
McIlroy plans to take the next two weeks off “to reassess everything” before reappearing for the second FedEx Cup playoff event, the Deutsche Bank Championship at TPC Boston.

“I’ll then play through the FedExCup and play Fry's.com and then I'm playing maybe a couple more after that. Dubai and China.”

Surprised he was so competitive after his lay off, he added: “I thought it might have taken me a few weeks, but I feel like it's right there and feels like I haven't been away for that long, which is nice. 

“I feel like I can be very competitive for the next few weeks.”

Whether he comes back in Boston as world No 1 or No 2 depends on the remarkable Spieth, who was five strokes behind Day at one stage before mounting a blistering back nine of six under 30.

Walking off the 10th green, Spieth was just one-under-par despite conditions that were yielding low scores. He responded with six birdies in his final eight holes.

He can only become world No 1 with McIlroy’s permission — a win with McIlroy tied second would be enough. And if he can hoist the Wanamaker Trophy, he will become the first player in the history of golf to win all three US-based major championships in the same season.

To date, Tiger Woods (2000) and Ben Hogan (1953) comprise the short list of those to win three major championships in a single season. Spieth can make it a trio with a win on Sunday.

“Michael did a great job keeping me in it,” Spieth said if his caddie’s role. “I was impatient on the front nine. I felt like I was playing some solid golf and I was 1-under through 10. I just wasn't scoring. My score did not reflect the way that I was playing, which has been a little bit of the story this week, minus two stretches of nine holes.

“And so once the one on 11 went, even though it was a simple up and down, I at least saw another birdie go. The one on 12 was nice. And we're off to the races. The holes started to look bigger. A lot of times it just takes one to go for me to really find that extra confidence, that extra little pop in my stroke.

“And on the back nine it was nice to get in the zone. The holes that I didn't birdie, 10 just barely missed, on the back nine, 14 was short in the heart. And then 15 was a great two-putt. So, yeah, very, very pleased to have a chance to win another major.”

History? Spieth says he’s just thinking of winning the PGA.

“Just to try to get my name on the Wanamaker Trophy, that's about it, that's the only history I'll be thinking of when we step on the first tee is you can hoist that trophy tomorrow and make it happen.

“This isn't as much in my head off the course as it was to try and get the Grand Slam, when I was getting ready to shoot for it the last couple of days at St. Andrews. At this point it would be really cool, but it isn't a Grand Slam.

“So for me it's going to be the same kind of just same level of focus as I'm sleeping tonight, I'll sleep just fine. And I'll go into tomorrow strictly for the history piece of trying to get my name on a different major. It's a goal of mine to capture all four throughout my career. I've got a great opportunity to get the third right now.”

Day made three birdies and two bogeys in his first five holes and was just one under for his round with 10 holes to play when he moved into a different gear.

A birdie three at the ninth was the first of six threes in a row— he parred the short 12th but boarded the 10th, eagled the 11th and birdies the 12th and 14th to get to 16 under.

A double bogey six at the15th, where he tugged his second into a bunker and failed to get the ball out the first time, could have been a huge blow. But he responded with a great birdie two at the 17th and a solid par at the last.

His 66 gave him a two shot lead of Spieth on 15 under par with Branden Grace (64) and Justin Rose (68) tied for third on 12 under.

Day’s perch atop the leaderboard is not an unfamiliar one — earlier this year, he was tied for the 54-hole lead at both the US Open and the Open Championship.

"I've been in position where I've been close to the lead going into Sunday, been tied for the lead," Day said. "The US Open I was tied for the lead this year going into the last day. But to have a two-shot lead is pretty sweet.

"I'm not looking at it as a negative, you can't, because you've got two shots and I've played phenomenal golf leading up to this. But now I've got to focus on round four. Everything I need to do is just make sure that I focus and prepare myself for tomorrow, make sure I get enough rest, make sure I get hydrated, because it is going to be warm tomorrow.

"And really kind of mentally prepare myself to know that things may go wrong tomorrow and things maybe go right. But you've got to make sure that you just keep pushing forward. And that's the mindset I need to take into tomorrow, and not really think about anything else."

Tiger Woods, meanwhile, added a 73 to his opening 75 to miss the cut by two strokes when he resumed on Saturday morning —  the first time in his career that he has missed the cut in three successive majors.”

Asked the keys he's learned from having 54-hole leads in majors before, he said: "Really not trying to beat yourself. I think the hardest thing for a player is when they're trying to close, they kind of get if in their own way, start thinking to themselves if they can do it, if they can't do it, is the shot too hard, is the shot too easy.

"A number of things can happen, especially on a final round of a major championship. I've done all the hard work right now to get into contention, to have this lead. So tomorrow I just need to be patient with myself, need to make sure that I stay disciplined to my targets. It's all the boring stuff, really, that you guys don't want to hear. But it's really the honest truth that I'm trying to get out because I can't get in my own way."