(From IAAF web-site by Paul Warburton)

The women’s 20km could turn out to be the most exciting of the four races along The Mall on Sunday, 13 August.

For the first time in six championships the all conquering Hong Liu will be absent as the current Olympic and world champion is forced to give way to another talented Chinese trio.

But as in-form as Xiuzhi Lu, Na Wang and Jiayu Yang are, a battle royale awaits Antonella Palmisano and Maria Guadalupe González.

In different parts of the world, both have already made a telling mark on 2017.

Italy’s Palmisano was two very quick steps from rewriting the 27-year-old 10,000m track walk world record at Orvieto in April, and went on to win the European Cup by a literal street a month later in the Czech spa town of Podebrady.

In fact, had she not stopped to pick up an Italian flag, twice, 50 metres from the finish that saw her finish in style, she would also have beaten her personal best 1:27:51, but lost out by seven seconds.

However, the former IAAF junior World Cup winner will be all but joined at the hip by González. To say that 2016 was a pivotal year for the 28-year-old former boxer doesn’t do it justice.

Mexico has been festooned with medals since a first Olympic silver in 1968 - but all won by men. Only Graciela Mendoza in 1991 had broken the male mould on a global level to win an IAAF World Walking Cup silver.

But González went one better last year to take the top step of the podium at the revamped World Team Championships in Rome after Liu was latterly disqualified.

In so doing, she set an area record 1:26:17 and then duelled all the way with Liu to a silver at the Olympics. Just for good measure, González won the IAAF Race Walking Challenge pocketing $25,000 for her pains.

So far this year, she’s had two Challenge wins, the first at altitude demanding Ciudad Juárez in March, the second a quick 1:28:09 that was also a record for the Pan American Cup at Lima in May.

“This win is very important in my preparation for the World Championships. I am satisfied where I am at in the lead-up to London.” Just how much will be challenged by a host of outsiders.

Apart from China’s trio and Palmisano, there is the intriguing return of Eleonora Giorgi.

Palmisano would be the first to acknowledge she’s stepped out of the shadow cast by her team-mate and 1:26:17 European Cup silver medallist, but Giorgi has been laid low with injury, and London will be a severe test of her depleted training.

South America’s women walkers have finally come of age. Three of them should be at the sharp end of the race - but how long is the big question?

Brazil’s Erica de Sena, wife of 50kms walker Andrés Chocho, currently leads the Challenge standings after a win at La Coruna in June, second in Ciudad Juarez, and another win in Monterrey where she entered at the last minute and still triumphed.

If there is to be a dark horse coming up The Mall rails, Paola Pérez is poised to play the part.

The Ecuadorian took a sledgehammer to her previous 1:33:25 best when she won the country’s championships in April by notching 1:29:06, and the previous mark had only stood a year.

If not Perez, then Peru’s Kimberley Garcia who was second in Lima behind González in an eye-catching 1:29:15.

There is a clutch of other sub 1:30:00 performers who have a chance. But it would be a brave person to bet against a certain Italian, Mexican or one of the Chinese for top honours.

Paul Warburton for the IAAF