Rory McIlroy's new putting technique continued to pay dividends as the world number three took command of the WGC-Cadillac Championship at Doral.
McIlroy had finished third, sixth and 20th in his first three events of 2016 before a missed cut in the Honda Classic last week prompted him to switch to a "crosshanded" putting method he last used in 2008.
The 26-year-old needed 33 putts in his opening 71 but just 25 on Friday and carried on where he left off on Saturday, taking 28 putts in a 68 which was the joint second lowest score of the day.
That meant McIlroy turned a two-shot deficit to a three-shot lead over defending champion Dustin Johnston and halfway leader Adam Scott, who carded rounds of 71 and 73 respectively.
McIlroy got up and down from a greenside bunker to birdie the par-five first and picked up another shot from seven feet on the fifth, before a birdie on the eighth - despite finding two bunkers - took him into the outright lead for the first time.
Scott had bogeyed the difficult fourth and missed from nine feet for eagle on the eighth, although the tap-in birdie meant he trailed playing partner McIlroy by a single shot as he looked to claim back-to-back wins following his victory in the Honda Classic.
McIlroy extended his lead with a birdie on the 10th and when Scott bogeyed the 13th after failing to get up and down from a greenside bunker, the Northern Irishman was three shots clear.
Scott responded with one of the shots of the week on the 14th, his recovery from a fairway bunker catching the edge of the trap but still finishing just nine feet from the hole.
The former Masters champion duly converted for birdie and was joined on 10 under by Johnson, who had picked up a shot on the short par-four 16th.
However, Johnson then bogeyed the last after a wayward drive and Scott did likewise on the 17th, meaning McIlroy's par save from a greenside bunker on the last put him firmly in pole position in pursuit of a third WGC title.
Phil Mickelson, Danny Willett and Bubba Watson were five shots off the pace on seven under, with Sergio Garcia, who was second to Scott at the Honda Classic, fellow Spaniard Rafael Cabrera-Bello and India's Anirban Lahiri two shots further back.