A dramatic last 100 metres saw leader Lyu Xiuzhi disqualified, leaving Chinese teammate Yang Jiayu to take gold in the women’s 20km race walk.
The chief judge’s red card was flashed in front of Lyu with seconds left, but it was so quick, and caught in the moment, she made for the line regardless only to discover her finish had already been recorded.
A cracking race came down to just four when the afterburners were lit at 16 kilometres, and the order of medals was still undecided with the line in sight.
Lyu and Yang put the hammer down to forge a tiny gap between them and Maria Guadalupe González, but the Mexican is made of strong stuff as demonstrated when taking silver at the 2016 Olympics and gold at last year’s IAAF Race Walking Team Championships.
Even with the pain etched on her face, González strove to get level with Yang and Lyu until the judge’s intervention decided the order of things.
Italy’s Antonella Palmisano was dropped with two kilometres to go, but alone to the line, she found to her joyous surprise a bronze medal awaited her.
Erica de Sena from Brazil had the race of her life to claim fourth and a South American record after hanging on to the leaders for all but the last three kilometres.
Sandra Arenas furthered the continent’s cause by snatching a Colombian record for fifth.
Ana Cabecinha from Portugal was a fine sixth with Kimberly Garcia from emerging Peru claiming a Peruvian record for seventh.
From the gun, a large group of 20 formed at the front with Palmisano nudging just ahead of Gonzales and Lyu towing the rest to 22:22 at five kilometres.
It was a lot faster than last year’s Olympic Games when it was also hot. And unsurprisingly, it told shortly after six kilometres when that score of competitors became a mere 10 vying for the medals.
Right at the back, neutral athlete Klavdiia Afanaseva was straining to hang on as the elastic binding all started to stretch.
But it was clear where the medals were going with the rest of the field trailing by more than 50 metres.
Halfway saw the clock stopped at 44:10 for the leaders, but Cabecinha and Afanaseva had dropped off by a vital few yards.
Garcia was next to suffer, and by 12 kilometres the lead group was cut to six, with Palmisano and Gonzales joined by De Sena, Arenas and the Chinese pair.
Arenas was unable to respond to a shift up though the gears that brought 1:05:33 for 15 kilometres, and when all was laid on the line, it became a terrific sprint to further excite a large crowd spread all along The Mall.
In the end, gold went to the same country that it did in 2015, only this time it was a new success for China to champion.
Yang had already recorded sub-1:27:00 in 2017 to underline her pedigree, and although the dynasty that was former champion Liu Hong appears over, the production line from a major race walking force just keeps on turning out the goods.
There is a footnote for all new mothers wondering if they should get back into sport.
Less than three months after giving birth to her first child, a delighted Claire Tallent was out on The Mall recording 1:33:05 for 43rd, amazing given the circumstances.
At the finish, she went over to husband Jared, 2012 Olympic champion but forced out of these championships with a hamstring injury, and collected baby Harvey to show off to the TV cameras and spectators on the course.
It seems there are other prizes worth having besides medals and money.
Paul Warburton for the IAAF