A hole-in-one boosted Justin Thomas to the lead after a wild third round at the WGC-Mexico Championship in Mexico City Saturday, but three of the biggest names in the game are breathing down his neck. World No. 8 Thomas moved to the top thanks in no small measure to his ace at the par-three 13th, where his tee shot from 232 yards took a big hop and disappeared into the cup on the second bounce. He carded 66 for 12-under-par 201 at Club de Golf Chapultepec, one stroke in front of fellow American Dustin Johnson (66) and two clear of compatriot Phil Mickelson (68) and Northern Irishman Rory McIlroy (70). "I knew it was just a good, smooth six-iron," Thomas told reporters of his ace. "I just absolutely flushed it and it was cool to see the gallery go nuts up there. I hadn't hit too many shots exactly how I wanted to today. That was the first one and I liked the result." Thomas is not as famous as his three closest pursuers, but the 23-year-old is having a brilliant season, with three victories in his past eight starts. World No. 1 Johnson struggled to hole putts in the first two rounds, but he drove the green at the par-four first and sank a 20-foot eagle putt to find some confidence, staying in the hunt for his second consecutive victory. An otherwise excellent round was marred only by a bizarre incident at the 16th hole, where his approach shot struck branches of a tree and disappeared. "I heard it clip the tree but I figured it was just going to be there in the bunker or just short of the bunker," said Johnson. After taking a stroke-and-distance penalty, he hit his fourth shot onto the green, moments before a bystander saw his ball fall to the ground. Johnson could only offer a rueful smile before sinking a 14-footer to salvage a bogey from what could have been a considerable wreck. "I'm playing really well, really confident in the game, feel like I've got a lot of control with the golf ball," said a confident Johnson. But he will have to be near his best Sunday to catch Thomas and stave off Mickelson and McIlroy. Mickelson drove the ball poorly but enjoyed a couple of lucky breaks, while McIlroy by contrast was rock solid. — Reuters