On a swirly Chicago morning, Brigid Kosgei delivered a dizzying head-twister of a performance to blow away Paula Radcliffe’s world marathon record. The Briton’s mark of 2hr 15min 25sec had stood, imperious and unchallenged, for 16 years. Yet Kosgei obliterated it by an astonishing 81 seconds.

Wearing a variant of the controversial Nike ZoomX Vaporfly Next% running shoes that had helped to propel Eliud Kipchoge to become the first man to break two hours for 26.1 miles on Saturday, the 25-year-old Kosgei blasted home in 2hr 14min 4sec – a time that had seemed unthinkable when dawn broke over the Midwest.

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It was a time that dazed and dazzled pretty much everyone watching. As the American distance star Molly Huddle put it afterwards: “2:14 – holy crap, what is life right now?”

Incredibly, Kosgei believes that she could go on to lop another giant slice off her shiny new record. “I think 2:10 is possible for a lady,” she said. “I am focused on reducing my time again.”

After this, would anyone dare bet against her? The whispers had grown during the week that Kosgei was gunning for Radcliffe’s record. The 25-year-old had advertised her sensational form last month by winning the Great North Run in 64:28, the fastest time for a women over 13.1 miles, and was said to be flying in training. And when Saturday’s gusts were tranquilised, and the forecast cold and sunny conditions arrived, it was clear that a serious attempt was on.

The first mile was run at breakneck speed, but that only encouraged Kosgei to press harder on the accelerator as she covered the first five miles in 25:10 – way inside world‑record pace. Some on the course wondered whether she had overcooked her pace and might eventually boil over. It never happened. She continued to look the model of grace and efficiency, her head and upper body textbook still as she urged her two male pacemakers on.

She went through halfway in 66.59 – more than a minute faster than Radcliffe’s time in setting her world record in 2003 – and another telling surge shortly afterwards meant it clear that the record was in her grasp.

Facebook Twitter Pinterest Kenya’s Brigid Kosgei crosses the finish line. Photograph: Kamil Krzaczyński/AFP via Getty Images

“I was not expecting this,” she said shortly after crossing the finishing line. “But I felt my body was moving, moving, moving so I went for it. This is amazing for me.”

She was joined by Radcliffe, who looked understandably shocked as she shook Kosgei’s hand. Could you blame her? Since 2003 she has held the most treasured possession of her illustrious career. Now it had been torn from her. No wonder she admitted it was a bittersweet moment.

“If you had told me when I set it in 2003 that it would last that long I wouldn’t have believed it,” Radcliffe said. “But I always knew this time would come – and when I saw how fast Brigid was running I knew the record would go if she could maintain her pace.”

Quick guide Flying footwear Show Hide Flying footwear The Nike Vaporflys were announced in a blaze of publicity and controversy before the Kenyan Eliud Kipchoge first attempted to run 26.1 miles in under two hours in May 2017. At the time, most people scoffed Nike’s claims that the trainers – which use a carbon plate and special foam – provided a 4% improvement in running economy. However the results have since proven them to be largely right. Over the past 17 months, the five fastest men’s marathon times in history have all been set with the latest incarnation of the shoe – which is called the Nike ZoomX Vaporfly Next% – while yesterday Brigid Kosgei was wearing them in setting the women’s world record in Chicago. Kipchoge, meanwhile, used another version which has not been yet been declared legal to go sub two hours in Vienna on Saturday.

Her agent, Federico Rosa, has had a worrying number of banned athletes. They include Asbel Kiprop, the former world 1500m champion, Jemima Sumgong, the 2016 London marathon and Olympic champion, and Rita Jeptoo, who won this race in 2013. But there is no suggestion of wrongdoing by Kosgei or Rosa.

Afterwards, when questioned by the Guardian, Kosgei pointed out that she trained in a different camp to Kiprop, Sumgong, Jeptoo, before adding: “Each and every person can run clean, we must work hard.”

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Some will raise eyebrows because of the fact that Kosgei was wearing Nike’s souped-up shoes, which have been estimated to give 60-90 seconds of performance benefit over its rivals, and have dominated distance running since 2017. That does not seem quite fair given the IAAF rulebook states that “shoes must not be constructed so as to give athletes any unfair assistance or advantage – and any type of shoe used must be reasonably available to all in the spirit of the universality of athletics”.

However the president of world athletics, Seb Coe, does not regard this as a pressing concern and even intimated that he is relaxed about this new technology. No serious runner doubts the advantage these shoes bring. As Jacob Riley, an unsponsored athlete who was 10th in the men’s race, said later: “They feel like running on trampolines.”

And on a stunning day in Chicago few appeared to care about such trivialities as Kosgei bounced and bounded into history.