Shane Lowry tees off his second round from one-over today with Graeme McDowell five-over after his first round.

“It was good, all aspects of my game were working pretty well today,” McIlroy told Sky Sports.

I drove the ball well and I took advantage of that, but I think the big thing was that I putted well.

“I didn’t putt so well at Riviera last week so went back to my old putter. I was trying a new one last week and it didn’t quite work out the way I wanted to.

"I was comfortable on the greens today and held some nice ones coming in.”

After starting from the 10th, McIlroy holed from 15 feet for an eagle on the par-five 11th and birdied the 15th and second before dropping his only shot of the day on the fourth after coming up short of the green with his approach.

Three birdies in the last four holes put McIlroy in pole position to go one better than 12 months ago when he finished second to Dustin Johnson, who struggled to an opening 76.

“I’ve always played well at altitude,” McIlroy added. “I finished second in Crans (Omega European Masters) last year, second here last year – I think I’ve got the altitude pretty figured out, I’ve got a pretty good formula for it.”

McIlroy also performed well on the difficult poa annua greens at Chapultepec and added: “You have to read it as well as you can, try and start it on your line and if it goes in, it goes in.

“That was sort of the saving grace last week, I knew everyone was struggling on the greens. If a putt misses and you’ve hit a good putt you just have to step up to the next one and try again. That’s what I did today, I had a really good attitude on the greens and it paid off.”