Kelvin Kiptum has set a world record in the Chicago Marathon, finishing in 2 hours, 35 seconds to shatter fellow Kenyan Eliud Kipchoge's old mark by 34 seconds on Sunday.

Sifan Hassan of the Netherlands also took advantage of cool and cloudy weather that's considered ideal for a marathon to win the women's race in 2:13:44 — the second-fastest ever for a woman at that distance.

Kiptum won the London Marathon in the spring in 2:01:25 and shaved almost a minute off the world record set last year in Berlin by Kipchoge, a two-time Olympic champion and the most successful marathoner ever.

"I knew I was coming for a course record, but a world record — I am so happy," Kiptum said.

"A world record was not on my mind today, but I knew one day I would be a world record-holder."

Kipchoge also broke the 2-hour mark in 2019 in a specially designed Vienna exhibition that does not qualify for the world record.

Hassan's time is second behind the women's world record of 2:11:53 set last month in Berlin by Tigist Assefa of Ethiopia.

Assefa shattered the women's world record by more than two minutes.

Marathon records have been tumbling of late, with new models of a 'super shoe' that can only be worn for one race seeing runners hit times previously unheard of.

More than 47,000 runners took part in Sunday's event.