Playing in the 57kg opening round match, Sachin was up against one of the strongest contenders for the title, Gaurav Bidhuri of Railways Sports Promotion Board. However, Sachin held his nerves and came up with a skillful boxing display before completing a 4-1 victory.
Another Haryana pugilist and South Asian Games champion Ankit Khatana made his way into the 75kg quarter-finals after he outshined Himachal Pradesh's Dharm Pal by a unanimous margin.
Meanwhile, Telangana's Savio Dominic Michael (54kg) and Goa's Ashok Patil (67kg) too progressed into the last-eight stage with identical 4-1 victories. While Savio defeated Jharkhand's Krishna Jora, Ashok Patil got the better of Himachal Pradesh's Mohan Chander.
Chandigarh's Kuldeep Kumar (48kg) and Sachin were among the other boxers to make progress on the third day of the Championships. Kuldeep booked a berth in the quarter-finals after an easy 4-0 win over Rajsthan's Sushil Sahran. Sachin went attacking from the word go against Roushan Kumar of Bihar during a 71kg opening round bout as the referee had stopped the contest and declared him the winner.
In the 75kg, Maharashtra pugilist Nikhil Dubey continued his excellent run in the tournament and sailed into the quarter-finals. He beat Telangana's Venu Mandala with an RSC verdict in the Last-16 match.