A 212-metre hole-in-one was the highlight of Justin Thomas's upstaging of Rory McIlroy and Dustin Johnson on day three of the World Golf Championship in Mexico City.
With world No.1 Johnson and No.3 McIlroy trading the lead during the first two rounds, 23-year-old American Thomas fired a five-under-par 66 at Club de Golf Chapultepec on Saturday (Sunday AEDT).
Thomas climbed to 12 under and will take a one-shot lead over big-hitting Johnson (66) into Sunday's final round, with McIlroy (70) and Phil Mickelson (68) sharing third at 10 under.
World No.8 Thomas was gaining momentum on the leaderboard before a stunning hole-in-one from 212m at the par-3 13th.
"You don't get to make them too often, let alone in competition, so it was awesome to see the gallery go nuts" Thomas said.
Thomas, who has three US PGA Tour wins this season, will be paired with Johnson and McIlroy in a superstar final group.
"It's cool; playing in the final group with DJ and Rory is something I haven't experienced before," Thomas said.
In his first tournament since injuring his rib in early January, four-time major winner McIlroy said an aggressive Sunday gameplan would be needed.
"You don't get a chance to win a WGC every week, so I'll go out there, be aggressive and hopefully it's good enough," McIlroy said.
Meanwhile, the Australian contingent are on track for their worst ever result in a WGC event.
Since the WGC concept was created in 1999, the only occasion an Australian hasn't finished in the top 25 was the match play event in 2000.
Sam Brazel emerged as the Australian most likely to prevent that unwanted record, carding a hard-earned 70 to share 38th place at even par.
The Tamworth export was paired with world No.6 Jordan Spieth, who miraculously fought his was back into the tournament at seven under with course-record 63.
"I feel one under was a good score considering I was a little nervous playing with Jordan, but I settled in," Brazel said.
"Jordan was playing sensational golf and holing a lot of good putts.
"It was awesome to have a front-row seat to his round."
Defending champion Adam Scott clawed his way back up the leaderboard with a 68, but the world No.7 will start Sunday a distant 16 shots off the pace in 53rd place.
Scott Hend's 73 leaves him sharing 66th place at seven over, while Victoria's Matt Griffin plummeted to last place at 19 over with a 77.