(Reuters) - Shubhankar Sharma continued his sensational run of form at the WGC-Mexico Championship to retain a two-stroke lead after the third round on Saturday, but the Indian was still not ready to contemplate the possibility of winning.

Mar 3, 2018; Mexico City, MEX; Shubhankar Sharma plays a shot on the fifth hole during the third round of the WGC - Mexico Championship golf tournament at Club de Golf Chapultepec. Orlando Ramirez-USA TODAY Sports

The 21-year-old, playing in his maiden PGA Tour event and first World Golf Championships tournament, remained the man to beat after a two-under-par 69 at Club de Golf Chapultepec in Mexico City.

But if he showed a few nerves with some loose shots down the stretch on Saturday, that will be nothing compared to what he is likely to experience on Sunday when he attempts to pull off one of the greatest upsets in recent golf history.

“I don’t really want to think about it,” Sharma said after posting a 13-under 200 total for the tournament.

“That would put too much pressure on me.I just want to go ahead and enjoy myself. Tomorrow will be a lot of fun with a lot of good players in the mix.”

A highly-credentialled group of four players are sure be breathing down his neck in the final round with American Phil Mickelson (65), Spaniards Sergio Garcia (69) and Rafa Cabrera Bello (69) and Briton Tyrrell Hatton (64) all on 11-under.

Mickelson, who has not won since the 2013 British Open, will be paired with Sharma in the final round.

Defending champion Dustin Johnson (68) is also in contention, three strokes behind, while Justin Thomas trails by four after surging into contention with a 62, the day’s best score.

Sharma started the third round solidly with three birdies in the first six holes but was a mediocre one-over the rest of the way.

Just when the wheels looked like they were falling off at the par-four 18th, however, he got up-and-down from a greenside bunker, reading a 13-foot par-saving putt perfectly and coaxing the ball into the middle of the cup.

“I got off to a great start,” said Sharma. “Made a few mistakes coming in, but I’ve done a fairly good job of the distances and the yardages.”

The Asian Tour regular was referring to the difficulty gauging the distance the ball flies in the thin air at more than 8,000 feet (2,438 meters) above sea level.

Sharma, who would become the first player in 30 years to win in his first PGA Tour start if he prevails on Sunday, is already a twice winner on the European Tour this year.

Creditable though those victories in South Africa and Malaysia were, however, they were achieved against nothing like the quality of players who will stare him down on Sunday.