The game was a Sicilian Defence opening and it looked to be a dead equal position when Amonatov made an inexplicable blunder by ignoring a queen+rook battery on the b-file.
"It was a lucky win for me today," commented Rahman.
GM Abhijeet Gupta deployed Sicilian Defence with black against IM Himal Gusainas the match ended in a draw.
In the B-Category with 783 players being held simultaneously and the tournament was won by Subhra Saha of West Bengal with nine points. For his victory, Saha won Rs 2.51 lakh.