The 19-year-old Hadhoum put the disappointment of a poor finish in Montreal last year behind her as she powered across the finish line in 56min 47sec.

She instantly put herself into the lead with a phenomenal swim and managed to avoid crashing on the 20-kilometre cycle in the wet weather that brought several riders down producing a leading 5km run to ensure victory.

"My swim is my best segment, so I was quite disappointed last year because the Junior World Championship was moved to a duathlon, and I finished seventh," said Hadhoum.

"So this year I was going to go all in in the swim.

"And then on the run I just went full gas.

"I am really happy with my performance today, I was not expecting it." 

Mexico's Jimena Renata De La Peña Schott was closing in on Hadhoum towards the end of the run but did not have enough left in the tank to catch her.

However, she was still delighted by the 56:54 performance which earned her silver in front of Hadhoum's compatriot Manon Laporte who crossed the line in third 15 seconds off the pace.

The race began just as light rain was slowing down which proved to be catastrophic for five riders who crashed out and subsequently had potential times replaced with Did Not Finish in the standings.

Hannah Prosser of New Zealand, Hungarian Nora Romina Nádas, Canada's Sidney Clement, Olivia Logan of Britain, and American Ruth Pardy all suffered in the slippery conditions. 

Batista then produced a stunning run to win the men's event where the top three all finished within five seconds of each other.

He never reached the front of the pack, conserving energy, until he burst out of the transition and worked his way into a lead that saw him register a 51:11 time for what is only the fourth win of his career.

The Portuguese athlete was then followed across the line by Frenchman Nils Serre Gehri in 51:14 before Canadian Mathis Beaulieu just two seconds later.