Newly crowned world No.1 Rory McIlroy has a two-shot lead at the WGC-Mexico Championship, but American duo Bubba Watson and Justin Thomas will be hoping to close the gap on day two.
McIlroy is looking to become just the second player to win all four World Golf Championship events this week, with Dustin Johnson currently the only player to do so.
With top-five finishes in his last five starts, McIlroy continued his hot form with a six-under par score of 65 at Club de Golf Chapultepec.
Thomas and Watson both impressed and are in touching distance of McIlroy at four-under par, but will need to keep their momentum going if they are to keep up with the Northern Irishman.
Three players share T4, one being Bryson DeChambeau who knows everything he needs to about altitudes, something that has a big effect on ball distance in Mexico. Joining DeChambeau in at three-under par is South African Louis Oosthuizen and Canadian Corey Conners.
McIlroy started his day on the 10th hole and wasted no time in getting under par, after he stuck his 274-yard second shot at the par-5 11th just 16 feet from the hole, before rolling it in for eagle.
Another birdie at the 15th and McIlroy made the turn in 33, before making four further gains at the first, sixth, eighth and ninth, with his only dropped shot of the day coming at the fourth.
Defending champion Dustin Johnson, who has won the WGC-Mexcio Championship three times in the last five years, failed to make his mark and struggled throughout, shooting a five-over par score of 76.