Leading by four shots in the final round, Trishul gave away the advantage as he shot a four-over 76.
Delhi-lad Ankur Chadha, starting nine behind the leader, caught up with the Bangalore-lad by the 16th hole and after a brilliant shot on the final hole, Ankur three-putted for a bogey which avoided a play-off situation.
The 19-year-old Trishul finished the tournament with an aggregate of four-under 284 to grab his maiden title on the Tata Steel IGU Indian Amateur Golf Tour while Ankur had to settle for the second place, just a shot behind.
Ainesh Ahluwalia finished fourth at 290 while Jaibir Singh and Manu Gandas shared the fifth place at 292. Aman Raj was seventh at 293 while Vikram Rana was eighth at 294.
"I am thrilled to win my maiden title. I am elated that I achieved the feat in front of my home crowd," said Trishul after his victory.
"I had not envisaged a threat from Ankur. I thought Udayan would go all out and was considering a late charge from him," added the winner.