Johnson has won five WGC titles WGC-Mexico third-leader leaderboard-16 D Johnson (US); -12 R McIlroy (NI); -9 P Reed (USA), P Cantlay (US), S Garcia (Spa), C Smith (Aus); -8 I Poulter (Eng), K Aphibarnrat (Tha) Other selected: -6 T Woods (USA), T Fleetwood (Eng); -5 P Casey (Eng), F Molinari (Ita); -4 L Westwood (Eng), T Hatton (Eng); -3 D Willett (Eng); +1 R Knox (Sco); +3 P Mickelson (US)
US Dustin Johnson moved four strides ahead after three rounds of the WGC Championship in Mexico at Chapultepec.
The 34-year-old world number three, two lead on the half stage, was six clear mid-way through the third day and placed a five under 66 to reach 16 below.
Rory McIlroy stays second after a 68 and mixes seven birdies with four bogeys.
Patrick Reed birdied the last three holes in a 64 and is nine under, while Tiger Woods had a four-putt in his 70 and is six under with Tommy Fleetwood.
The third member of the last group, Matt Kuchar, two of the leadership at night, had three double bogeys in a 79 drop to one below.
Johnson sent his ride to the 367-yard par four-second hole just three feet from the flag and rolled into the eagle putt.
After eight holes, his lead was six after McIlroy's third bogey of the day, but two holes later, the advantage was only two.
With a gap of 45 holes without a shot down in the tournament, the twice – former champion made a double bogey in 10th place after he hit twice trees, while McIlroy rolled into a 34 – foot birdie putt at nine – where he took four putts in round three – and threw up to three feet for another bird in the next one.
Johnson responded with successive birdies and added two more to the back nine, while at last McIlroy saw a birdie opportunity to cut the opening to three slides past the cup.
Woods birdied the opening two holes, tapped at the first and then pitching up to two feet of 137 yards, but he double bogeyed the 15th after taking three putts of three feet, before finishing with his sixth birdie of the day.