Rory McIlroy must match the biggest comeback in the history of the Masters and close an eight-shot gap on runaway leader Dustin Johnson if he's to win the green jacket and complete the career grand slam.

World No 1 Johnson cruised to a seven-under 65 to lead by four shots on 16-under par but McIlroy has vowed not to throw in the towel.

"I haven't really made a good run on a Sunday and it's my 12th time here so it's about time," McIlroy said after carding a 67 to move up to tied 10th with Brooks Koepka, Tommy Fleetwood and Hideki Matsuyama on eight-under.

Determined to put the leader under pressure, he added: "I feel good. My game is there. I have shown that over the first two days and it is just a matter of committing, trusting and playing the same way.

"If I can put up another number, and I will probably need something a few lower than I shot today, at least set a number in the clubhouse for the guys to chase."

Scoreboard

In truth, everything depends on Johnson and if he falters, McIlroy likely needs the final round of his life with nine world class players ahead of him.Sung

The Holywood star produced a brilliant display with the putter, ratting in six birdies in a five-under 67 to move up to tied tenth on eight-under par.

But he still fell further behind the unflappable Johnson who rapped in an eagle and five birdies in a bogey-free, seven-under 65 to lead by four shots from Korea’s Sungjae Im (68), Mexico’s Abraham Ancer (69) and Australian’s Cameron Smith (69) on 16-under.

McIlroy is just four strokes out of second place and while he has had five top-10 finishes in his last six Masters starts, he believes it’s high time he made a Sunday charge for the title and at least makes the leaders sweat.

“I have probably given myself too much to do after the 75 on the first day but we will see where eight under leaves me at the end of the day and try to go out and shoot a good score tomorrow,” said the Co Down man, who needs the biggest comeback since Jack Burke Jr. came from eight strokes behind Ken Venturi to win with a 71 in 1956.

“I haven’t really made a good run on a Sunday and it’s my 12th time here so it’s about time. I feel good. My game is there. I have shown that over the first two days and it is just a matter of committing, trusting and playing the same way.

“If I can put up another number, and I will probably need something a few lower than I shot today, at least set a number in the clubhouse for the guys to chase.”

Tied for 28th after 36 holes, six strokes behind Johnson, Abraham Ancer, Cameron Smith, Justin Thomas and Jon Rahm, McIlroy raced to the turn in 33 thanks to some incredible putting inside 12 feet.

After making a five footer for par at the first, he knocked in a seven footer for birdie at the second, followed quickly by par putts at the fourth (5 ft.), fifth (12 ft.), sixth (9 ft.) and seventh (4 ft)

He then birdied the eighth from nine feet, walking after his putt in disgust only to see it topple in the back door, then punched out of trees to 13 feet at the ninth and drained that too to get to six under.

He remained six shots off the lead, however, as Johnson eagled the second with a spectacular approach to 18 inches and then birdied the third to go two shots clear of Im on 12-under.

While McIlroy continued his amazing run with a birdie from six feet at the 10th, Johnson knocked in a 40 footer for a two at the fourth to stretch his lead to three shots.

McIlroy would not go away and while he was fortunate to find the bunker at the 12th after mishitting his tee shot, he holed out for a two to get within five of the leader and move into the top 10.

The gap was quickly back to seven strokes as Johnson stiffed his approach to the seventh to go to 14-under and McIlroy three putted the 13th from ten feet, lipping out from three feet for par.

He then did well not to drop a shot at the 15th, rashly going for broke and finding water when blocked out by trees rather than laying up.

“I try to view everything as a learning experience, but yeah, I'll look back at that and rue some of the shots that I hit and some of the thought processes I had and just try to learn from it and be better the next time,” he said.

He bounced back with a two at the 16th and then parred home. But he knows he has his work cut out tomorrow after Johnson birdied the 13th and 15th to go four-shots clear on 16-under

As he waited for Johnson to finish, he said: “I just need to go out and shoot a good one tomorrow and see where it puts me, but I have zero thoughts about winning this golf tournament right now.

“I just have to try to do the same thing I've done the last couple of days, go out and try to hit every fairway, try to hit every green, try to make a birdie on every hole if you can.”

If it was a good day for McIlroy, it was also a good one for Open champion Shane Lowry, who made six birdies in a four-under 68 to move up to tied 20th alongside his hero Tiger Woods on five-under.

As Graeme McDowell missed the level par cut by a shot after a 73 and Mallow amateur James Sugrue finished four shots further back after a 71, Lowry shot 69 in the delayed second round to make it a shot to spare.

The highlight was a brilliant chip-in at the 14th that he joked was the second best chip he’d seen at Augusta after playing partner Woods’ incredible chip-in at the 16th in 2005.

“The chip on 14 was just incredible,” said Lowry, who impressed playing partner and defending champion Woods with that piece of magic. “It was one of those where I said to Bo, just chip this to 20 feet, and it just came out perfect.  It kind of checked on top of the hill.  There's probably not too many worse leaves on the golf course than there, so that was nice to do that. 

“As I said [to Tiger], it's probably the second best chip I've ever seen on this course.  His on 16 was a little better under the circumstances.  That's what I said to him walking up 15. 

“And then I fatted a wedge shot on 15 that stayed on the bank, so yeah, the golfing gods were kind of on my side this morning.”

McDowell missed chances at the 12th and 13th to get back to level par before finding water with his second to the 15th, running up a six that left him needing two birdies in his last three holes to make the cut.

While he clawed back a shot at the 17th, he missed the 18th green and came up and inch short with his attempt to chip in.