M Pranesh clinched the title in the Rilton Cup, the first tournament of the FIDE Circuit, to become India's 79th chess Grandmaster.
The 16-year-old Pranesh crossed the 2500-rating threshold and became a GM, having completed his three norms before the Rilton Cup.
To become a GM, a player has to secure three GM norms and cross the live rating of 2,500 Elo points.
Tamil Nadu player Pranesh topped the charts in the tournament, which brought together 136 players representing 29 national federations.
He won his first norm at the 18th Delhi GM Open in January 2020, followed by the second at the Sunway Sitges International Chess Festival in Spain in December 2021.
He won the third norm at the Asian Continental Chess Championship in November last year.
Nineteen-year-old Koustav Chatterjee had recently become the country's 78th Grandmaster during the National Senior Chess Championship.