Russia's Valeriy Borchin strode to gold in the men's 20km walk on Sunday ahead of compatriot Vladimir Kanaykin, while Luis Fernando Lopez celebrated after his bronze gave Columbia its first world championships medal.
Borchin, hair plastered to his forehead with sweat, pumped his fist in delight as he crossed the finish line in downtown Daegu after one hour, 19 minutes and 56 seconds of hard toil in high humidity.
The 25-year-old Olympic gold medalist and defending world champion met Kanaykin at the line less than a minute later with an embrace and a Russian flag, while Lopez overhauled China's Wang Zhen in the final stages of the race on the streets of the South Korean city.
Borchin, who collapsed in the heat and humidity of Osaka at the 2007 world championships, looked the strongest of all the finishers, while other walkers collapsed in exhaustion as soon as they crossed the line.
Home hope Kim Hyun-sub slumped to the ground after finishing sixth and was whisked away on a stretcher, swaddled in cold towels for treatment, though emerged later under his own steam to the relief of the South Korean spectators.
Borchin said it had been a difficult year for him injury-wise but he was so happy to retain the title.
"It was very tough here because when I won gold in Beijing I was not very well known and nobody took me as a favourite," he said. "After winning the gold medal in Berlin I was under more scrutiny and everyone wanted to beat me so that was very tough for me."
Lopez was delighted to finally get his country on the medal table at a world championships.
"For me, this bronze medal feels like a gold," he said proudly. "This medal shows that Columbia can dream of becoming a better country."