Shubhankar Sharma set about extending his lead as the third round of the WGC – Mexico Championship began at Chapultepec Golf Club.
The 21 year old from India has enjoyed a remarkable rise in recent months, winning the Joburg Open in December and last month's Maybank Championship to top the Race to Dubai Rankings presented by Rolex.
Sharma followed those achievements by establishing a two-shot halfway lead on his WGC debut in Mexico City, and was not fazed by Sergio Garcia catching him on 11 under before he had a chance to complete the opening hole.
Having eagled the driveable opener in both of the first two rounds, Sharma settled for a birdie from seven feet on day three to regain the outright lead.
Garcia had birdied the first two holes, but while he bogeyed the third after missing the green on the par three, Sharma hit a superb tee shot to six feet and converted to reach 13 under par for the week.
That was three clear of Garcia and Americans Pat Perez and Xander Schauffele, who were three under and one under for the day respectively.
England's Tyrrell Hatton and Spain's Rafa Cabrera Bello were on nine under alongside major champions Dustin Johnson, Phil Mickelson and Louis Oosthuizen.
Sharma briefly went four clear when he reached the par-five sixth in two and birdied, but failed to get up and down on the eighth as he dropped a first shot of the day.
At 13 under his lead had been trimmed to one by Perez, who birdied the 11th and 12th, with Hatton and Mickelson – seven and six under for their respective rounds – on 11 under.
