As a result, they have now secured their places in the quarter-finals of the second PSA World Series tournament of the 2016-17 season.

England's Willstrop, who eliminated world number three Omar Mosaad in the first round, beat Mohamed Abouelghar in a gruelling 70 minute encounter.

Willstrop lost the first game 9-11, before going on to win the next two and take control of the match, 11-9, 11-6.

Abouelghar levelled the match in the fourth game, winning it 11-5, before the Englishman rallied to claim the fifth and decisive game 11-7.

"That was an hour and a bit of frantic intensity," said Willstrop.

"I had to play very, very well to beat him.

"I’m just so pleased to get through, I want to keep on playing."

Willstrop will now face South African Stephen Coppinger after he beat Malaysian qualifier Nafiizwan Adnan, 11-7, 5-11, 9-11, 11-4, 11-9 in another epic match.

Elsewhere in the men's competition, Egyptian brothers Mohamed and Marwan Elshorbagy will meet in the last eight after they both came through their second round clashes.

World number one Mohamed beat Chris Simpson of England 10-12, 11-9, 12-10, 11-5, while Marwan defeated Peruvian Diego Elias 3-11, 11-4, 11-4, 11-6.

In the women’s draw, three-time US Open champion David of Malaysia came back from the brink of elimination to defeat Nour El Tayeb of Egypt and keep her campaign alive.

El Tayeb dictated the play early on, winning the first two games 11-4, 11-9.

The experienced David, who has won a total of 80 PSA Tour titles, managed to turn the match around in the third game and launched a comeback that was completed after 53 minutes when she sealed the win 4-11, 9-11, 11-4, 11-6, 11-7.

"I wasn’t firing in the first game and a half and she made it very hard for me," said David.

"I knew I had to fight all the way. 

"I trained really hard over the summer during the off-season and I wasn’t going to go down without a fight - I pushed to the limit and I’m really pleased to win that 3-2.

"I didn’t let up - I knew I wanted to keep going until the very end and that’s what I did."

Elsewhere, Egypt's Raneem El Welily saw off the challenge of New Zealand’s Joelle King, while another Egyptian, current world number one Nour El Sherbini, defeated Sarah-Jane Perry of England 11-5, 11-4, 8-11, 11-6.

She will now take on Alison Waters after the Englishwoman edged Egyptian qualifier Salma Hany Ibrahim.

Waters required 63 minutes, and a fifth game tie-break, to get the better of the talented youngster, securing the win at the second time of asking to come through 12-14, 11-1, 7-11, 11-4, 14-12.

Second round action from the bottom half of the draws gets underway tomorrow at Drexel University’s Daskalakis Athletic Centre.