McIlroy has won two WGC titles, the 2014 Bridgestone and 2015 Match Play WGC-Mexico Championship first division leaderboard-8 R McIlroy (NI); -7 D Johnson (US); -5 J Thomas (US), M Kuchar (USA); -4 T Hatton (Eng), G Coetzee (SA) Other selected: -3 I Poulter (Eng); -2 S Garcia (Spa); -1 A Rai (Eng), T Fleetwood (Eng); level D Willett (Eng), T Woods (USA); +1 R Knox (Sco), +2 L Westwood (Eng); +4 J Spieth (US); +8 P Mickelson (US)
Rory McIlroy from Northern Ireland scored an eight-under-63 to take a one-shot lead after the opening round of the WGC-Mexico championship.
The 29-year-old world number eight started its round on the 10th and placed seven birdies and an eagle.
American Dustin Johnson, winner in 2017, is the second after a bogey-free 64.
Englishman Tyrrell Hatton composed four birdies on the last nine in a 67 but defending champion Phil Mickelson had eight bogeys and a double in a 79.
McIlroy, who won the last of his 14 PGA Tour titles at the Arnold Palmer Invitational in March last year year, eagled his 10th after sending a two-iron tee shot to five feet on the 307-yard par four.
He was two clear after pitching up to three meters from 123 yards at 13 before he dropped his only shot from the round at 15 after both his drive and second were influenced by trees left.
I a Poulter returned six birdies in a 68, while co-Englishman Tommy Fleetwood, two Johnson runner-up two years ago, dropped two shots into his last three holes in a 70.
Tiger Woods, winner of 18 WGC titles from 1999-2013, also started on the 10th at Club de Golf Chapultepec and after a double bogey on his 10th, three consecutive birdies made their way to a level par 71.
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