"I'm really happy", Shubhankar said. "Good approach shots are very important if you want to shoot low numbers".
He added he was enjoying his first visit to the country. "I've been driving the ball really well, especially today, it's a fantastic feeling".
The biggest mover on the day - and the most likely challenger to Sharma - was Sweden's Christofer Blomstrand, who produced a quite sensational 10-under-par 62 on Saturday that included eight birdies, two eagles and two bogeys.
DAVID Howell hauled himself up the Joburg Open leaderboard with a superb three-under second round of 69 in South Africa this morning. "He showed me a sign this morning and I just went out there and did what I had to do".
A field of 240 players is split over the Bushwillows and Firethorn courses for the first two days.
Davidse, 28, was quick to recover from a dropped shot on the sixth and went on to make further gains on the eighth, 12th, 14th and 17th before ending a productive day in style by holing a huge birdie putt on the 18th. Morrison carded a 67 and Van Rooyen a 70 in the third round, and both are realistic contenders for the top prize should Sharma falter. He will hope to produce something special on Sunday as he seeks to add to the PGA title he won at Eye of Africa a year ago. I can't wait for tomorrow.
Nineteen players were unable to complete the second round because of a storm.
Dylan Frittelli, the big pre-tournament hope of South Africans after winning the Mauritius Open last weekend, had a 71 and is out of contention 15 shots off the pace.
It's all set up for a thrilling 2018 edition of the Joburg Open, but will anyone be able to stop India's steam train, Sharma?