The 20-year-old Egyptian's victory at the PSA World Women's Championship in Malaysia also vaults her past Massaro into the sport's number-one ranking.

"I'm dreaming right now, I didn't imagine I could win this match," said El Sherbini.

She had looked like a champion all week.

In the quarterfinals she crushed Nicol David -- the defending world champ who had dominated the sport over the past decade -- ending the Malaysian's bid for a ninth world title.

She then swatted aside her compatriot Nouran Gohar in the semifinals to set up a rematch of the 2013 final that was won by Massaro.

Massaro seemed headed for her second world championship as El Sherbini, appearing rattled, committed several unforced errors and questioned the officials' decisions in dropping the first two games 6-11 and 4-11.

But she recovered in the third with a series of devastating volleys and held Massaro off 11-3, 11-5, 11-8 in the last three games.

"Me and Laura's games have always finished in five games. This time was going to be my turn and I was confident knowing that I was playing good," El Sherbini said.

Massaro paid credit to El Sherbini after the match.

"It's amazing for her to have come back from two games down. I will take this defeat on the chin and return stronger," she said. 

El Sherbini's defeat of David earlier in the week left the Malaysian's hometown fans stunned and provided further evidence that her decade-long dominance of the game may be over.

The Malaysian has a record eight world championships but has suffered a dip in form over the past year. In September she surrendered her phenomenal nine-year stranglehold on the world's number one ranking.

But David expressed confidence that she could stay among the sport's elite despite falling to a previously unthinkable world number five, and she shot down speculation that she may consider retiring soon.

"Disappointed -- but not even close to retirement," she tweeted late Thursday after her loss.

No world championship was held in 2015 after the event was suddenly called off in December amid controversy, with its previous promoter claiming security concerns in Malaysia prevented it being staged.

Malaysian officials denied any security threat and accused the promoters of a ploy to secure more financial support.