The world number two beat the world number one 6-11, 4-11, 11-3, 11-5, 11-8 in an epic contest in the Malaysian capital.

At 20-years-old, she has become the youngest-ever winner of the biggest prize in women's squash, breaking the record set by Susan Devoy in 1985.

El Sherbini will replace Massaro as world number one because of her triumph with the victory avenging her 2013 final defeat to the 32-year-old, who was searching for a second title.

"I'm dreaming right now, I didn't imagine I could win this match," said El Sherbini, the first female Egyptian to become world champion.

"I want to say thanks to the Egypt team and everyone here for all the support that pushed me to the end.

"Laura is a very tough player and even until the end I didn't think I could do it.

"At 2-0 down I though it was over."

Massaro was gracious in defeat after losing the title from the jaws of victory.

"It's an honour and privilege to play in a World Championship final, it's the pinnacle of our year," she said.

"I’m obviously disappointed to lose but she played an amazing match from 2-0 down.

"I have to take it on the chin and come back again.

"Thanks to everyone who has helped me, my family and coaches who can't be here, it's been unbelievable.

"It's been an amazing tournament and we as players couldn't have asked for more this week."