He missed a 6-footer for a birdie at the par-5 sixth and bogeyed the eighth after a poor drive to turn in 34, 1 under par.
"The ball was sitting down just enough where I didn't think I could clear that tree", he said.
Johnson still has not made a bogey this week through 54 holes, but a double bogey on the 10th hole showed that he is indeed human and slowed his march to this title, if only for one hole.
Tiger Woods has won more major championships than anyone other than Jack Nicklaus but his putting went badly awry during the third round of the WGC-Mexico Championship on Saturday.
Amazon plane crashes in Houston killing all on board
A dive team with the Texas Department of Public Safety will be tasked with finding the black box, Hawthorne said. The largest piece from the Boeing 767 that police have recovered is 50 feet long, Hawthorne told the newspaper.
Patrick Reed, Patrick Cantlay, Australia's Cameron Smith and Spain's Sergio Garcia are tied for third, seven shots back of Johnson at 9 under. He was too firm with his bogey putt and lipped out again, and finally tapped in for double.
Johnson almost threw away his six-shot lead through eight holes when McIlroy made a 35-foot birdie putt on No. 9, and then Johnson ran into some serious tree trouble on the 10th hole.
McIlroy converted from 15 feet at the 14th to match Johnson's birdie from either further out, with the duo then making two-putt gains at the next and adding close-range birdies at the par-four 16th. It shot straight up in the air and hit the tree in front of me. He said he would need as many opportunities on Sunday and even a better score. "I'm thinking it's going to at least take 10 (under) to maybe even a 59 depending on how he finishes the day".
"It's going to take a really special day tomorrow", Reed said.
Asia shares rise on U.S.-China trade deal optimism, Aussie tumbles
Australian officials said there was "confusion" over the situation, and they were consulting their Chinese counterparts. News that Dalian, one of China's biggest ports, banned imports of coal from Australia also weighed on the Aussie.
Johnson had a two-shot lead to start the third round over McIlroy and Matt Kuchar, whose hopes for a Mexican sweep of PGA Tour events fizzled with a 79.
On the final hole of his day, the par-four ninth, Woods drove into a trap.
"D.J.is playing very well".
The following three-putt was the first time ever in his PGA Tour career in which he as followed up a four-putt with a three-putt.
MWC 2019: Foldable smartphones and 5G set to dominate this year’s show
However, the company recently confirmed that this year's MWC will witness the world's first 5G foldable phone . Huawei has scheduled a live MWC event at 21:00 BJT, which is 14:00 local time in Barcelona.