India's Shubhankar Sharma held on to his two-shot lead at the World Golf Championship ©Getty Images

India's Shubhankar Sharma remains on course for a shock victory at the World Golf Championship as he held on to his two-shot lead with a par-saving putt on the final hole in Mexico City.

The 21-year-old debutant is two in front of the rest of the field heading into tomorrow's final day at the Club de Golf Chapultepec.

Sharma carded a round of 69 to end on 13-under-par.

American Phil Mickelson, seeking his first victory since 2013, was among the main movers on day three as he shot a six-under-par 65.

Mickelson is in a chasing pack which also includes Spaniards Sergio Garcia and Rafa Cabrera Bello and England's Tyrrell Hatton, all of whom are on 11-under.

Defending champion and world number one Dustin Johnson of the United States is part of a group of four players who are a further three shots behind Sharma on 10-under.

American Phil Mickelson is among the chasing pack at the World Golf Championship ©Getty Images
American Phil Mickelson is among the chasing pack at the World Golf Championship ©Getty Images

Justin Thomas of the US produced the round of the day, carding a course record 62 to cut the deficit to Sharma to four strokes in a tournament that is one of the four annual World Golf Championships organised by the International Federation of PGA Tours.

Such is the low-profile nature of Sharma, the youngest of the 64-strong field competing at the event in the Mexican capital, that he was mistaken for media by Mickelson.

The Indian player approached the American five-time major winner to introduce himself during the third round.

"He thought we were media and he said, 'Not right now, after the round,'" said Sharma.

"Then he just realised and said, 'So sorry, I thought you were media'."