Twenty-year-old Thai International Master Prin Laohawirapap defeated India's Arjun Erigaisi at the Fide Chess Olympiad in Samarkand.
Despite the individual upset on the top board, the Indian Open team defeated Thailand with a 3-1 margin in the opening round.
The defeat caused Arjun Erigaisi, who was rated nearly 400 points above his opponent, to drop out of the top 10 in live ratings.