The 35-year-old clocked a provisional three hours, 36 minutes and three seconds, beating the previous best of 3:36:39 he set in winning the European title in Munich last year.
Russian German Skurygin, stripped of his world gold in Seville in 1999 for doping, gave valiant chase and won silver in 3:36:42. German Andreas Erm took bronze in 3:37:46.
Korzeniowski has dominated the event since winning Olympic gold in 1996. He also won an unprecedented 20-50 km double at the 2000 Sydney Olympics, but did not attempt the feat here.
