Clifford stunned Algieria's Paralympic and world champion Abdellatif Baka in the final, finishing in 3min 47.78sec at the Dubai Club For People Of Determination.

It was Baka's record time of 3:48.29, set at the 2016 Paralympic Games in Rio de Janeiro, that was broken by Clifford.

This time, Baka had to make do with bronze and a time of 3:49.30, while Anton Kuliatin of Russia completed the podium with second-place in 3:47.91. 

"It’s unbelievable" Clifford, a bronze medallist at the last World Para Athletics Championships in London two years ago, said. 

"I didn’t expect to win but I was dreaming to win. 

"Winning the gold medal against such a tough field is huge confidence for next year at the Tokyo 2020 Paralympics.

"I want to win double gold at Tokyo 2020 [1500m and 5,000m] but I have to work hard for this."

Brazil's Rayane Soares Da Silva was the winner in the women's 400m T13 with a personal best of 57.30sec.

She finished in front of Carolina Duarte of Portugal in 57.46 and Leila Adzhametova of Ukraine in 57.55.

"I didn’t realised that I was leading," said Soares Da Silva.

"The last 100m was tough and my feet started to ache. 

"But I am happy to finally finish it."

In men’s 100m T51 final, Piispanen Toni of Finland beat the world record holder, Peter Genyn of Belgium, with a time of 20.33.

Genyn was second in 20.50, while Edgar Cesareo Navarro Sanchez of Mexico came third in 22.48.

Earlier in the day, the qualification rounds began after the event was opened by Dubai Sports Council vice-president Mattar Al Tayer.

Around 1,400 athletes from 118 nations are participating in an event due to last until November 15.