Adrian Zielinski of Poland claimed weightlifting gold by the narrowest possible margin in the men's 85kg category on Friday.
Zielinski scored a total of 385kg, the same weight lifted by Apti Aukhadov of Russia, but the Pole was awarded the gold because he weighs 130 grams less.
It was Poland's first gold medal of the Games and third overall after a silver in shooting and a rowing bronze.
Aukhadov had the lead after snatching 175kg and Zielinski missed one kilo more.
But the situation reversed in the clean and jerk, with the 22-year-old Pole hit 211kg and Aukhadov scoring just 210.
He buckled under his last dramatic effort at 213, which would have won the gold.
Iran's Kianoush Rostami claimed bronze with a total of 380kg, five kilos short of the leading pair.