Rory McIlroy was all cut up over the rough as Tiger Woods put himself in position to chase down Francesco Molinari and capture his fifth green jacket and his 15th major at the Masters.

After Tony Finau blasted an eight-under 64 to set the target at 11-under, Woods shot a clinical 67 to join him in a tie for second, two strokes shots behind the unflappable Italian, who chiselled out a superb 66 thanks to a clinical sand save at the 18th.

US Open and PGA champion Brooks Koepka is lurking in fourth place just three strokes off the pace after a 69 with Webb Simpson (64) tied for fifth with Ian Poulter (68), four strokes behind.

But McIlroy is making up the numbers again, a hopeless 12 shots behind his Ryder Cup teammate on one-under par after another rollercoaster 71.

He blew his slim chance to make a charge with a two-over par front nine, then camouflaged another disappointing performance with some back nine fireworks. After following a birdie at the 10th with a bogey at the 11th, he went birdie-par-eagle-birdie from the 13th before ending his day with a bogey.

It all added up to more Augusta disappointment, and a growing sense that the Masters monster grows bigger for McIlroy every year.

"I've just been making too many mistakes," said the 29-year old, who has made 14 bogeys in 54 holes after taking three entire events (216 holes) to reach that tally on the PGA Tour this season.

"I've been making the birdies, and doing the things that you need to do around here. But if I've missed a green,  or put myself out of position, I haven't got it up and down. 

"It's been one of those weeks where I just didn't quite have it."

Wayward driving was just one of his problems, and he blamed Augusta's second cut, mowed at just 1 3/8-inch, for some of his headaches.

"The rough this year is about a quarter or half an inch longer than it usually is, and it's just hard to get control of your ball out of it," he said. "And I just haven't driven it in the fairway enough to have control going into these greens."

Unlike the one dimensional PGA Tour tests he faces week-in, week-out, Augusta National requires canny course management, precision iron play and deft putting inside 10 feet.

McIlroy was found lacking in all three departments and as a result, any birdies he made were quickly negated by mistakes and he will have to wait until 2020 to try to complete that career grand slam.

"I will go out and play to the end," he said as the later starters took advantage of perfect conditions. "It is a 72-hole golf tournament so play all 72 as hard as I can. Try and play a good round of golf tomorrow.

"It's okay. As I have been saying, no matter what happens at this golf tournament, it is not going to change my life either way. I will get ready for the new few weeks. There is a lot of golf to be played this season." 

He looked upbeat at the start, ripping a 320-yard tee shot down the first before walking off shaking his head as a 25 footer stopped on the lip.

It was clear he wasn't firing on all cylinders as soon as the second where he hit his tee shot out of position on the right and short-sided himself with his approach, failing to make birdie.

He couldn't chip and putt from greenside for a birdie at the driveable third, but even after holing a 35 footer down the hill for a two at the fourth, he was soon on the back foot.

His first big mistake came when he short-sided himself left at the par-three sixth, missing from around three feet for par after a brilliant chip.

Deflated by that mistake, he was between clubs and bunkered his approach to the seventh after driving into the left rough, pull-hooked his tee shot into the woods at the eighth and could only make par, then bogeyed the ninth after another short iron from the first cut came up short in a bunker.

Out in 38 when he had set a target of "32 or 33", he played the back nine well, following a birdie-bogey start for home with a birdie from the woods at the 13th, a spectacular eagle three from eight feet at the 15th and another two at the 16th before bunker trouble led to a bogey at the last.

"I made six bogeys out there today, and if you want to get yourself in the mix at any golf tournament, that's just a case of too many mistakes," he said.

"I am making the birdies, and I've had a couple of eagles or whatever, but I have made too many mistakes."

He added: "It's not that I am playing bad golf — I am under par, but I'm just not enough under par.  I just made too many mistakes — missing it left on six, putting myself out of position on a couple of the par‑5s, where I can't go for the green in two. Little things like that where on a different day, it could be a different result.  

"It's not as if anything is glaringly obvious in terms of what's lacking in my game, it's just been one of those weeks where I haven't quite got the momentum that I needed to get."

Molinari is the man to beat today after he birdied the sixth and eighth to turn in 34 before racing home in 32 by following with four birdies in a row from the 13th with a spectacular sand save at the 18th.

He’s made just one bogey in 54 holes — a staggering achievement considering the difficult of the test — and knows that he doesn't just have to worry about Woods but also the chasing pack.

"I don’t only have two worry about him - there are a few other who can shoot a score,” Molinari said of Woods.

"The course was gettable today and someone can shoot seven, eight or nine under and make a move up the leaderboard."

After coming close to winning his 15th major in The Open at Carnoustie and the USPGA at Bellerive last year, Woods knows today will be a war of attrition.

”We’ll just go out and see what the course gives us,” said Woods, who hasn’t won a major for almost 11 years. 

"There is some weather coming in but this will be different. 

"Normally we have a sleep in on Sunday if we play well. Tomorrow it’s going to be an early wake up call, going off two tees in threesomes.”