Dustin Johnson will take a two-shot lead into the weekend of the WGC-Mexico Championship as Rory McIlroy failed to build on a flying start to his second round.
Leaderboard WGC-Mexico Championship
McIlroy carried on where he left off from his superb, opening 63 and birdied three of the first four holes to extend his overnight lead to four, but he bogeyed the sixth for the second day running and then needed four putts to get down from 15 feet at the ninth.
Image: Rory McIlroy led by four but then endured two bad holes on the front nine The 29-year-old managed to steady the ship as he made eight pars and a lone birdie at 14 on the back nine, but his 70 left him two behind the 2017 Mexico champion Johnson, who added a 67 to his opening 64 and completed 36 holes without a single blemish on his scorecard.
Ryder Cup team-mates Sergio Garcia, Tommy Fleetwood, Ian Poulter and Tyrrell Hatton are all placed in the top 10 at the halfway stage along with Tiger Woods, whose impressive 66 featured one of the shots of the year as he almost holed a remarkable 130-yard second from a fairway bunker at his final hole.
WATCH: Tiger's bunker thriller Tiger Woods pulled off one of the shots of the year as he almost holed a high cut from the sand in Mexico
McIlroy made the ideal start when he converted from three feet for birdie on each of the first two holes, and he added another at the fourth before coming to grief at the long sixth, where his ambitious second failed to clear the water and he did well to hole from six feet for bogey.
But his solid run of short-range putting came to an abrupt end at the ninth, where his 15-foot birdie putt from the fringe trickled four feet past the cup before he lipped out twice and ran up his second six of the day which gifted the outright lead to Johnson.
Rory McIlroy's lead at the WGC-Mexico Championship suddenly disappeared when he needed four attempts to get down from 15 feet midway through his second round.
The American again plotted his way cautiously around a Club de Golf Chapultepec layout which became much firmer and faster for the later starters, picking up two birdies on the front nine and nailing 10-foot putts for further gains at 10 and 12 to move to 11 under.
Johnson settled for six relatively untroubled pars to close out another bogey-free round, while McIlroy got his challenge back on track with a welcome birdie at the 14th, although he then missed another chance from three feet at the long 15th.
Image: McIlroy managed to play the back nine in one under to stay in the hunt McIlroy parred safely home to stay at nine under along with Matt Kuchar, who birdied the first four holes and went on to add a 66 to his first-round 67, while Garcia and Fleetwood are two shots further off the pace going into the weekend.
Fleetwood became the first player since 2009 to open a round with two eagles as he drove the green at the first and rattled in a 20-footer for a two, and he pitched in for another at the second to vault to five under for the tournament.
Tommy Fleetwood enjoyed a dream start to his second round in Mexico as he followed an eagle-two at the first with this chip-in for another eagle at the second.
The Englishman added three more birdies before blotting his card with a rare miss from just inside three feet at 17, and his par at the last completed a 65 which earned him a share of fourth with Garcia, who mixed seven birdies with two late bogeys in his 66.
Poulter recovered from a double-bogey start to return an entertaining 68 which included four birdies and two bogeys over his last seven holes, while Woods bounced back from his frustrating, opening 71 with a six-birdie 66.
Image: Tiger Woods is six off the lead going into the weekend The 14-time major winner got two good putts to drop for birdie at the third and fifth, and he made further progress up the leaderboard when he picked up three shots in four holes from the 12th before he three-putted from 60 feet on the penultimate green.
Woods looked in danger of dropping another shot at his final hole when he pushed his tee shot into a fairway bunker and left himself blocked out from going directly at the green with his second, but he manufactured an outstanding high cut with a nine-iron which cleared the trees, pitched on the front-left part of the green and spun inches past the hole.
He would go on to miss the birdie chance from 12 feet, but his 66 represented a substantial improvement on his opening round, although it was not even close to matching the effort of defending champion Phil Mickelson, whose 65 was a remarkable 14 shots lower than Thursday and lifted him 31 places up the leaderboard.