Kenya's Brigid Kosgei has smashed Paula Radcliffe's marathon World Record which had stood for more than 16 years.
The 25-year-old clocked an impressive two hours, 14 minutes and four seconds in Chicago, beating Paula Radcliffe's best which was set in April 2003.
Kosgei finished a staggering six-and-a-half minutes ahead of Ababel Yeshaneh of Ethiopia who clocked 2.20.51, and third placed Gelete Burka, also of Ethiopia in 2.20.55.
Kosgei's marathon World Record comes just five weeks after she set a new half-marathon World Record of 1.04.28 at the Great North Run.
The two hours, 15 minutes and 25 seconds Radcliffe recorded in London had proved unbeatable for 16-and-a-half years.
Radcliffe was present to congratulate Kosgei at the finish, with her record beaten by well over a minute.
Kosgei - who won the Chicago Marathon in 2018 and the 2019 London Marathon - went through the halfway point in 1.06.59 and barely fell off the pace as she pressed on.
Kosgei said she had not set out with the expectation of eclipsing Radcliffe's historic mark.
"I am feeling good and happy because I was not expecting to run like this," the athlete said.
"But the course is good and I was able to run my best time."
Radcliffe had set her first marathon world record in Chicago in 2002 before lowering the mark in London the following year to the one that would prove persistently impossible to beat.
Radcliffe said: "We always knew the time was going to come and when I saw how fast Brigid was running in the first half of race I knew if she was going to hold it together she would do it.
"It was exactly 17 years ago today that I set my first world record in Chicago.
"That was a very special day for me and it is a very special day for Brigid today."
The men's race was won in a closely fought battle by Lawrence Cherono in 2.05.45.
The Kenyan finished just one second ahead of second-placed Dejene Debela of Ethiopia, and three seconds ahead of third-placed Asefa Mengstu, also of Ethiopia.
Defending champion, Great Britain's Sir Mo Farah, finished eighth in 2.09.58.
Sir Mo had sparked controversy in the pre-event build-up when he implied there were racial elements in questioning over his relationship with the disgraced coach Alberto Salazar.
The US's Daniel Romanchuk retained his wheelchair title in 1.30.26, almost three minutes ahead of Britain's David Weir, who came second in 1.33.31.
Likewise Switzerland's Manuela Schaer retained her wheelchair title, clocking 1.41.08.
Kosgei's achievement comes on an incredible weekend for marathon running, with Eliud Kipchoge breaking the two-hour barrier - albeit not under race conditions and therefore not a World Record - on Saturday.