MEXICO CITY (AFP) - Rory McIlroy fired seven birdies and one sensational eagle on the way to an eight-under 63 and a one-shot lead over Dustin Johnson at the WGC-Mexico Championship on Thursday (Feb 21).

Former world No. 1 McIlroy, now ranked eighth in the world as he seeks his first win since the Arnold Palmer Invitational last March, belted a 2-iron 307 yards at Club de Golf Chapultepec's par-four first - his 10th hole of the day.

It hit the front of the green and threatened the hole, McIlroy eventually making a six-footer for eagle.

His only miscue on the day was a bogey at the sixth, but he rebounded with a 20-foot putt for birdie at his penultimate hole, the eighth, to lead 2017 champion Johnson by one stroke.

Johnson had seven birdies without a bogey in his 64 and was two shots clear of Justin Thomas and Matt Kuchar.

Tiger Woods received a rapturous welcome from fans on the first tee, where he was introduced for his first competitive start in Mexico as "Tiger! Tiger! Tiger Woods".

He immediately hit his drive out-of-bounds on the way to an opening double bogey. He bounced back with three straight birdies at the fourth, fifth and sixth on the way to an even-par 71.

Defending champion Phil Mickelson, who edged Justin Thomas in a play-off last year, got off to a dismal start with an eight-over 79.