RORY McIlroy equalled the lowest opening round of his European Tour career to lead the way after day one of the WGC-Mexico Championship.
The Northern Irishman fired an eagle and seven birdies at Chapultepec Golf Club en route to his fifth first round of 63 and his lowest starting round on the European Tour since 2014.
That left him at eight under, one shot clear of 2015 and 2017 champion Dustin Johnson and three ahead of two more Americans in Matt Kuchar and Justin Thomas.
South African George Coetzee and Englishman Tyrrell Hatton are four shots off the lead.
McIlroy has not won on the European Tour since 2016 but has finished second five times since then and was showing the sort of form that has brought him four Major Championships.
Hatton finished a shot out of a play-off here last season and turned in level par with a birdie and a bogey before coming to life on the back nine. He holed from 16 feet on the tenth and sandwiched a beautiful tee-shot to tap in range on the par three 13th with up-and-downs from the sand on the 12th and 15th.
Thai Kiradech Aphibarnrat, Americans Billy Horschel and David Lipsky, and England’s Ian Poulter were five shots off the lead.
McIlroy said: “It felt pretty stress-free. I wouldn’t say it was easy. I hit a lot of good golf shots, I left myself a lot of tap-ins for birdies and had a nice eagle on the first hole as well.
“I think for the most part my wedge play was pretty good. I was able to control my distance as well, control trajectories well, but my putting felt great all year, so if I’m excited about anything in my game, it’s the way I’ve putted the last few weeks.
“Also just my attitude. I’m not putting myself under any pressure, I’ve sort of got things in a really nice perspective. I think that’s probably 80 percent of the reason why I’m playing this good golf over the first few weeks of the year.
“I saw some really good signs last year. I played myself into final groups and had some good chances to win and I think this year is just building upon the good stuff that I was able to do last year,” McIlroy added.
Dustin Johnson, who is pushing to recapture the World No. 1 spot from Hampshire’s Justin Rose, said: “I’m just trying to get it in the fairway and get a good number and coming in to these flags.
“The greens are tough, so you kind of want to leave yourself in the right position and today was a good day.
“I felt like I controlled the ball well. I gave myself a lot of opportunities. Missed a couple short ones, but that’s going to happen around here. I’m very pleased with the round.
“I just think it’s a really good course. Even being at altitude, it’s still a good golf course. Put this in the States and it would be extremely difficult.
“It plays a little bit easier because it plays shorter with the altitude but I like the golf course. It’s tree lined, it’s tight and if you play well, you can make a lot of birdies.”
Hatton, a member at Buckinghamshire’s Harleyford GC, said: “I’m pretty happy with the score. I have good and bad memories from last year so looking to have a good start and obviously four under is a nice way to start the tournament. Hopefully I can continue that way.
“I feel comfortable here. I like how the course kind of suits my eye. If I can hole some putts I should have a good week.”
Tiger Woods, who has won 18 World Golf Championship titles – four more than he has Majors to his names – said: “I got off to a bad start. Got it going after a little bit there, made three in a row.
“Couldn’t make any birdies after that for some reason. It is what it is.
“The people were fantastic. They were into it, they were excited, and they were yelling for Abe today. It was cool to see.”