Chicago - Kenya's Brigid Kosgei shattered Paula Radcliffe's 16-year-old world record Sunday, winning the Chicago Marathon in two hours, 14 minutes and four seconds.
Kosgei broke the mark of 2:15:25 set by Radcliffe in the London Marathon on April 13, 2003 as she won in Chicago for the second straight year.
Kosgei, the 25-year-old who also won in London in April and clocked the fastest half-marathon in history this year of 1:04:28 at the Great North Run, quickly separated herself from the women's field as she ran with two male pace-setters.
Lawrence Cherono made it a Kenyan double with victory in the men's race, as Mo Farah finished a distant eighth to end a week when he hit back at critics over his work with disgraced coach Alberto Salazar.
Kosgei crossed the finish line alone, with Ethiopians Ababel Yeshaneh and Gelete Burka a second and third in 2:20:51 and 2:20:55.
"I'm happy and I feel good," Kosgei said.
"People were cheering all along the course, which gave me more energy.
"I felt my body was moving, moving, moving so I went for it."
While the IAAF called the 2:17:01 clocked by Mary Jepkosgei Keitany at the 2017 London Marathon a "women only" world record posted without male pace-setters, it's Radcliffe's mark - so long untouchable - that has been the grail for female marathon runners.
The British great was in Chicago and posed for photos with Kosgei.
"I think we've always known that time was going to come," Radcliffe said. "When I saw how fast Brigid was running in the first part of the race, if she was able to hold that together, she was always going to beat the time."
Radcliffe had also held the Chicago course record of 2:17:18 - set in winning the 2002 race in what was then a world record.
"That was a very special day for me and it's a very special day for Brigid today," Radcliffe said.
Kosgei's performance continued a remarkable weekend in the punishing event, coming a day after fellow Kenyan Eliud Kipchoge became the first man to break two hours at the distance when he clocked 1:59:40.2 on a specially prepared course in a Vienna park.
Kosgei signalled her intentions with an astonishing first five kilometres in 15:28 - so far inside Radcliffe's world record pace that it seemed she might have ruined her chances out of the gate.
But she settled into a more sustainable rhythm, and powered relentlessly to the finish line.
Her halfway split of 1:06:59 had Kosgei comfortably inside world-record pace, and her lead expanded over the second half as her pursuers felt the effects.
The pace-setters dropped away in the closing kilometres, leaving Kosgei to break the tape alone, her arms raised in celebration.
Cherono won a men's race that came down to the wire in 2:05:45 - barely edging Ethiopia's Dejene Debela who was second in 2:05:46 with another Ethiopian, Asefa Mengstu, third in 2:05:48.
Last year's winner Farah was never a factor - finishing in 2:09:58.
The Briton - who set a European record in Chicago last year - was among an early lead group that began to disintegrate around the 10km mark, leaving half a dozen runners, including Cherono, setting the pace.
Kenya's Bedan Karoki challenged late but faded before the last turn toward the finish to leave Cherono, Debela and Mengstu to sprint for the line.
"All of a sudden when we reached 41 kilometres the (others) were not going again," Cherono said.
"I decided to kick and felt I was still having enough energy to sprint.
"I tried my luck, and it worked."
US distance running guru Salazar has been banned for four years by the United States Anti-Doping Agency for a string of doping violations.
Nike shut down its Oregon Project running group headed by Salazar, and four-time Olympic gold medalist Farah arrived in Chicago for his defence to find himself again denying any irregularities during his time with the coach.
Results on Sunday in the Chicago Marathon:
1. Lawrence Cherono (KEN) 2hr 05min 45sec
2. Dejene Debela (ETH) 2:05:46
3. Asefa Mengstu (ETH) 2:05:48
4. Bedan Karoki (KEN) 2:05:53
5. Bashir Abdi (BEL) 2:06:14
6. Seifu Tura (ETH) 2:08:35
7. Dickson Chumba (KEN) 2:09:11
8. Mo Farah (GBR) 2:09:58
9. Jacob Riley (USA) 2:10:36
10. Jerrell Mock (USA) 2:10:37
1. Brigid Kosgei (KEN) 2:14:04 - world record
2. Ababel Yeshaneh (ETH) 2:20:51
3. Gelete Burka (ETH) 2:20:55
4. Emma Bates (USA) 2:25:27
5. Fionnuala McCormack (IRL) 2:26:47
6. Stephanie Bruce (USA) 2:27:47
7. Lindsay Flanagan (USA) 2:28:08
8. Laura Thweatt (USA) 2:29:06
9. Lisa Weightman (AUS) 2:29:45
10. Taylor Ward (USA) 2:30:14