The 31-year-old triple world and Olympic 1,500 metres champion had needed to take more than seven seconds off her own 2023 world record of 4:07.64 but, despite a series of aids, managed just over one second.

She was helped by innovative new kit, super-spikes and, crucially, a phalanx of mostly male pacers who blocked the wind on the four and a bit laps of the Stade Charlety track where she set her 1,500m world record last year.

Dressed in a black one-pieced suit with black arm warmers, the diminutive Kenyan was swamped by her group of pacers, mostly men and all world class athletes themselves.

In a pre-designed plan, a group of five men ran in a line in front of her as "the shield" with American double Olympic bronze medallist Grant Fisher on her shoulder.

She was about on course at halfway but began to slip behind the coloured pacing lights inside the track and drifted on the final lap as she tied up over the last 200 metres.

Those male pacers meant, just as with compatriot Eliud Kipchoge's sub-two-hour marathon run with "in and out" pacers in 2019, that the new mark will not be recognised as a world record.

Kipyegon, however, was her usual upbeat self at the finish. "I'm tired but I feel good and I tried," she said, thanking the crowd of around a thousand people who had given her enthusiastic support.

"That is why I was coming here - to try to be the first woman to run under four minutes. It's only a matter of time but I think it will come our way. If it's not me, it will be someone else.

"So, yeah, I know one day, one time, a woman will run under four. I will not lose hope. I will still go for it and if there's not something like this, a special one, I think in a normal Diamond League, or anything, I will still go for it and I hope I will get it one day."

Britain's Roger Bannister was the first man to go under four minutes in May 1954, with compatriot Diane Leather the first woman to break five minutes later the same month. The current men's record is the 3:43.13 set by Hicham El Guerrouj in 1999.