MEXICO CITY – Dustin Johnson had yet to make a bogey through 45 holes as he took a five-shot lead to the 10th hole in Saturday’s third round of the World Golf Championships-Mexico Championship.

He was overpowering the course with both his prodigious length and exceptional accuracy. He was comfortable in the thin air 7,800 feet above sea level. And he had history in his pocket – he won here at Club de Golf Chapultepec two years ago and finished in a tie for seventh last year.

In other words, he looked unbeatable.

Then he turned into Al Czervik from Caddyshack.

His tee shot on the 10th hit trees to the right of the fairway and the ball was lucky to stay in bounds. His second shot as he stood up against a row of bushes hit another tree limb. His third shot, again from the row of bushes, hit another tree.

Johnson finally avoided some wood, chipping his ball on to the green. Two putts later, he walked off with a double-bogey 6 and his lead had slipped to just two shots, as Rory McIlroy had made birdie.

There wasn’t steam coming out of his ears. He didn’t slam any clubs, didn’t bark at his caddie and brother, Austin Johnson. No, Johnson’s MO includes a short memory and a laid-back nature that helps him overcome trouble.

“I knew I was playing well so I didn’t really let it bother me,” Johnson said.

The scorecard said it didn’t bother him. Johnson birdied the next two holes, added another on the 15th and another on the 17th and finished with a 5-under-par 66. He stood at 16 under through 54 holes and four shots clear of McIlroy (68).

“You’re not going to find anybody winning golf tournaments that are temperamentally weak,” said Paul Azinger, lead golf analyst for NBC Sports/Golf Channel. “And (Johnson) is proving that today.

“He’s Cool Hand Luke. Nothing bothers him.”

McIlroy said spotting Johnson four shots is a “tall order” to overcome. But he was right there when Johnson went sideways on the 10th.

“All of a sudden you go from 6 behind on the ninth tee to 2 behind on the 11th tee,” McIlroy said. “It can change that quickly, and that’s something I’m going to have to just keep reminding myself tomorrow with a bit of a deficit.”

Johnson will keep reminding himself to just keep doing what he’s been doing – pound the driver when need be, use long irons off the tee for accuracy, keep giving himself birdie chances and keep putting well.

He did that save for the 10th hole. He electrified the crowd on the second hole when his drive stopped 368 yards from the tee box and just four feet from the hole. He canned the eagle putt. He added another birdie on the fifth and the four on the back (he has 16 this week, plus the eagle). And he made clutch par saves on five holes.

“I’ve got a game plan out here, I’m not going to change it,” Johnson said. “Just going to play the golf course hopefully exactly like I have the last three days, but especially the way I’m going to attack the course, I’ll play just like I did.”