It was the little-known Kim Hyo Sim who pulled off a shock win, trouncing her namesake compatriot and Rio Olympic silver medallist Choe Hyo Sim by the huge margin of 12kg.

Kim couldn't hold back the tears on the podium as she received gold and then tried to break into a smile, but thought better of it with the frosty-looking Choe standing crestfallen beside her.

“I wanted to smile but I felt sorry for 'Onni' ('big sister'),” Kim told AFP.

Her win pushed the secretive nation past its record Asian Games record of four golds achieved in Incheon four years ago.

Kim, 24, told AFP she had struggled with a leg injury since her only international win, the Asian Junior Cup in 2013.

“I was able to do well at the national championships this year and get back into the team,” Kim said.

“I didn't represent my country for four years because of my injury. I can't quite believe it.” Kim was overwhelmed with emotion at her first senior championships gold as she sang the national anthem draped in the North Korean flag flanked by the stony-faced Choe.

“I couldn't stop the tears when I thought of (North Korean leader) General Kim Jong Un,” Kim said.

“It is thanks to General Kim Jong Un, the national team and the good environment for training that I won this gold medal,” Kim added.

Kim took an early 8kg advantage on Choe with a 113kg snatch and she never looked like yielding as she produced three flawless clean and jerks, the final attempt 137kg for a 250kg total.

It left Choe needing to better her Rio performance by 3kg to win and it proved beyond her powers as she could only manage 133kg in the clean and jerk to finish on 238kg.

Wamalun Rattanawan was delighted to take bronze on 225kg, the fifth medal for the consistent Thailand weightlifting team (one silver, four bronze).

Every lift was greeted ecstatically and noisily by the colourful band of Thai supporters who have lit up the Jakarta International Expo arena all week.

Wamalun's was the second bronze for Thailand in the event and the first medal in the 63kg class since Thingsuk Pawina won gold in 2006.

Weightlifting is North Korea's most successful sport and they came into the Asian Games as heavy favourites to top the medal standings given the absence of powerhouses China and Kazakhstan, suspended for multiple historic doping offences.

They have taken five of the eight golds on offer so far, with seven weight classes still up for grabs.