The Bangalore lad shot a level par 72 to stay at 3-under 141 after 36 holes after city-mate Udayan Mane shot a consecutive 1-under par 71 to stay a strike adrift of the leader.
Incidentally, Udayan's 71 was the best card of the day.
Patna lad Aman Raj was lying third at 143 after submitting a card of level par 72.
Pratap Atwal who matched the day's best score of 71 was tied for the fourth spot along with Manu Gandas at 146.
Syed Saqib Ahmed, Vikram Rana and Ainesh Ahluwalia were all tied for the sixth place at 147.
Trishul who began from the 10th, was in trouble on the par-5 11th where he hit right and furthered it on his second.
Despite a good chip, he could not make an up and down and missed a seven-footer for par.
He got into his wonted form making three birdies in the next four holes to be 2-under for the day.
However, on the 17th, after hitting in the left, he was back in the woods and chipped out on to the green from about 170 yards but missed the ensuing long par-putt to end up with a bogey.
On the back nine, things only got tougher for Trishul as he bogeyed the second which was nullified with a birdie on the fourth with a 20-footer effort.
With consecutive bogeys on the sixth and seventh, mainly owing to his short game, he did resurrect with a birdie on the par-3 eighth with a perfect 9-iron which left him about 10 feet from the pin.
"I could have hit more fairways than I did but my irons saved the day for me," said the 19-year-old.
"It is a tight leader board. It is too early to predict anything, although I would surely want to be on the top," he said.
Top scores after 36 holes
141 Trishul Chinnappa (69, 72); 142 Udayan Mane (71, 71); 143 Aman Raj (71, 72); 146 Pratap Atwal (75, 71), Manu Gandas (74, 72); 147 Syed Saqib Ahmed (75, 72), Vikram Rana (72, 75), Ainesh Ahluwalia (72, 75); 148 Lokesh Lakshman (74, 74), Hemendra Chaudhary (73, 75), Ankur Chadha (72, 76); 149 Yashas Chandra (77, 72), Pukhraj Singh Gill (73, 76), Nikhil S Sekhawat (71, 78)
--IBNS (Posted on 04-09-2013)