Rory McIlroy will go into the weekend just two shots off the lead at the World Golf Championships - Cadillac Championship after firing a scintillating seven under par 65 in the second round at Trump National Doral.
The World Number Three changed his putting grip to left-below-right coming into the week in Florida and the switch looked to have paid dividends as he took just 23 putts to surge into contention on Friday.
The Northern Irishman had held a share of the lead with three holes to play but Adam Scott made three birdies in his last four holes to get to ten under, two clear of McIlroy and defending champion Dustin Johnson.
Englishman Danny Willett, who finished second to McIlroy on the 2015 Race to Dubai, was then a further shot back, with American duo Charley Hoffman and Bubba Watson on six under.
McIlroy's change of putting grip has been the story of the week but the four-time Major winner insists he has always felt comfortable putting left-below-right, and hinted he may have changed sooner if World Number One Jordan Spieth had not been using the stroke.
"One thing that I was sort of worried about was McIlroy copying Spieth," he said with a wry smile. "That was my big thing. That was the whole thing for me.
"I feel like I played similarly from tee-to-green. That really hasn't been the issue over the past few weeks. But the putter was really what was the big difference.
There was a lot of big momentum putts in there that I had not been holing. So to see those drop today and to be as comfortable as I was, it feels really good - Rory McIlroy
"I'm very happy with where I'm at going into the weekend."
It had looked like five-time Major Championship winner Phil Mickelson would be the man to catch as he opened up a three-shot lead on the front nine, but he came home in 40 to sign for a 72 and slip to five under alongside Englishman Paul Casey.
McIlroy opened birdie-bogey before a run of four birdies catapulted him up the leaderboard.
Brilliant approaches to the fifth and seventh resulted in gains and sandwiched a 14-foot birdie putt, before an impressive save from the sand helped McIlroy turn in 32.
He made another up-and-down for birdie on the 12th, this time holing from ten feet, and a 23-foot putt on the par three 15th was followed by a brilliant 20-footer down the hill on the notoriously tough 18th.
Willett had hit the front early thanks to a birdie-birdie start but bogeys on the sixth and ninth sandwiched a further gain on the eighth. A birdie on the 12th came courtesy of a 13-foot putt and he then got up-and-down from a bunker on the 16th.
Australian Scott was a winner last week on the US PGA Tour and continued that form with eight birdies and two bogeys in a 66, while Johnson was flawless in a 64 that was the low round of the week so far.
Hoffman and Watson signed for rounds of 70 and 69 respectively, while Casey recorded a 68.
Two-time 2016 winner Charl Schwartzel was then at four under alongside India's Anirban Lahiri and American Jason Dufner, with Andy Sullivan, Bernd Wiesberger, Chris Wood and Spieth in the group seven off the lead.
