Fifth place would be enough to guarantee a second men’s title for Mola in a concluding race carrying a double points score, while Duffy could earn her second world gold with seventh place or better – although both could potentially finish even lower and still win overall, dependent on other results.

Mola took his first world title at last year’s Grand Final in the high temperatures of Cozumel where his main rival, Britain’s Jonny Brownlee, staggered to halt 400m from the finish when apparently poised to win, and had to be assisted over the line by his brother Alistair, the double Olympic champion.

Had Brownlee, who was deposited over the line in second place, been able to win under his own steam he would have earned his second world title following his 2012 triumph.

As it was, fifth place on the day proved enough for Mola to take the title by four points.

But tomorrow’s task is not as simple as it appears for the 27-year-old from Palma, Majorca, who has accrued 3701 points so far.

Mola started his 2017 campaign by winning titles on the Gold Coast, as well as in Yokohama, Hamburg and Edmonton.

But his form has suffered in recent weeks through injury and illness, and he was only 14^th in Montreal and seventh in the penultimate series event in Stockholm last month and his lead over 34-year-old fellow countryman Javier Gomez, five-times world champion, has been reduced to 340 points.

With 1,200 points on offer for the winner tomorrow Gomez appears to have a real chance of overhauling Mola to become the ITU champion for a sixth time.

The most successful ITU racer in history has already won the WTS events in Abu Dhabi and Montreal this year and returned to the gold standard by winning the Stockholm event last month.

More recently the Spaniard won the Ironman 70.3 World Championship in Chattanooga, USA.

Brownlee, meanwhile, is only sixth in the rankings on 2806, but his victory in Stockholm after two fourth places in the series indicated a return to form, and the Rotterdam course looks likely to offer him the chance of ending 2017 on a high.

 Duffy’s victory in Stockholm took her points total to 4000, leaving her almost 500 clear of Australia’s Ashleigh Gentle, who has 3507.

Gentle appears to be Duffy’s main challenger, although there could be a strong British contender in Jess Learmonth, who earned a breakthrough second place in Stockholm.

Switzerland’s 35-year-old Olympic 2012 champion and 2016 silver medallist Nicola Spirig is an intriguing addition to the startlist and can never be underestimated given her competitive pedigree.