The world number three has a two-shot lead at the halfway point.
Rory McIlroy has a two-shot lead at the WGC Championship in Mexico, after carding a stunning six-under 65.
McIlroy capitalised on an impressive opening round of 68, to produce an eagle and six birdies in the second round, as he looks to chase down the world number one ranking for the first time since 2015.
Should McIlroy progress to win the tournament in Mexico, and current number one Dustin Johnson finishes joint fourth or worse, McIlroy will secure the top ranking.
The highlight of McIlroy's second round was an eagle on the par-four 14th, which he holed from 151 yards out.
However, he missed a three-and-a-half-foot birdie putt at the 18th hole and bogeyed the 17th.
Speaking to media after the round, McIlroy spoke of his frustration about those shots.
"I would have taken a 65 starting today and I definitely would have taken a two-shot lead going into the weekend, so I'm in a great position."
"I'm kicking myself because I missed a couple of short ones coming in, but overall I'm in a good spot and looking forward to being in contention over the weekend."
It emerged that McIlroy was suffering from food poisoning in the early stages of this tournament, which left him sleep-deprived and weak.
But the symptoms had minimal impact on his performance as he worked himself into contention after the first round.
This is McIlroy's first competitive outing due to a rib injury.