There was barely anyone to watch his feat at a near-deserted Olympic stadium.
The greatest walker in history, Korzeniowski covered the last third of the race in hot and humid conditions on his own to cross the line in three hours 38 minutes 46 seconds.
Silver went to exhausted world record holder Denis Nizhegorodov of Russia, who looked close to collapse as he finished just over four minutes back, and bronze to another Russian, Aleksey Voyevodin.
The 36-year-old Korzeniowski, who is also a triple world champion, had already carved his name in walking history four years ago by winning the 20-50km double. No other man, indeed, has ever won the Olympic 50km race twice.
Korzeniowski grabbed a Polish flag as he entered the stadium and crossed the line holding it in his teeth.
No-one has trained harder or expended more sweat than Korzeniowski did for his Athens gold.
Justin Gatlin's 100 metres gold took 400 metres and around 40 seconds in all to secure, including heats. The Pole went 125 times further and competed for around 330 times as long.
The race had begun at 7 a.m. local time in an empty Olympic stadium -- the venue had been packed with 75,000 spectators only hours before for the men's 200 metres final. There were just a handful of cleaners, officials and journalists looking on as the sun broke clear of the horizon.
The few onlookers witnessed an electric start, however, when the Chinese trio hurtled away and exploded the 54-man field within minutes.
It proved a suicidal tactic for Han Yucheng, second fastest in the world this year. He received his first of three warnings for lifting after five minutes, dropped away and was later disqualified.
That left a six-man pack, including Korzeniowski, Nizhegorodov and Australia's Nathan Deakes, who won bronze in the 20km walk in Athens, 100 metres ahead inside the first 10 minutes.
The 24-year-old Nizhegorodov, who broke the Pole's world record in June, and Korzeniowski led from 10 to 30km as the leading group was whittled down to four.
World bronze medallist Andreas Erm of Germany lost touch before being disqualified and sportingly shaking the judge's hand.
With just over an hour to go, the Pole and Australian attacked but Deakes's elation was shortlived as he was red-carded after his third warning.
He looked close to tears as he stopped by the side of the road, holding his capped head in his hands.
Perhaps the Deakes family had already had its quota of luck this year -- a few months ago his mother won a $1 million jackpot while playing a one-dollar slot machine at a Melbourne casino.
Korzeniowski, on his own with a third of the race remaining, was 51 seconds ahead of Nizhegorodov at 40km and he increased that to 1:32 by 45 before sealing his triumph.
Based in the far north of France, he is often spotted beginning his training walks in one country, crossing the border into Belgium and returning to his French home for lunch. He is known there as "Le Roi de Macadam" (The King of the Tarmac).
