The American world number 30's performance demonstrated that she is back at the top of her game following a career-threatening Achilles injury, which kept her out for 10 months.

The match did not completely go her way, however, and she had to fight back from losing the first game 11-8 to her Egyptian opponent before eventually winning the next three 11-6, 11-6, 11-5 to clinch a 3-1 victory.

Following her win, Sobhy said: "It's been such a long journey.

"I know I came back at Tournament of Champions but I really had my eye set on this tournament.

"I really wanted to prove to myself that I've got this and told my coaches that I wanted to go on my own to do it by myself.

"I wanted to prove to myself that I've come all this way and I've fought back from injury and I can still beat the top people.

"The fact that I've come so far and gone through so much and built myself back up from the ground and got this win against a top six player, I'm really happy.

"I have a massive team around me and it has been a major team effort - I couldn't have done it without all of their help and support.

"It has been a long process, but they have stuck by me and I can't thank them enough.

"If there was ever a tournament to win then this would be a good one.

"I love Chicago - being the home girl is awesome and having everyone's support."

She will now face New Zealand's Joelle King after she knocked out former world number one Laura Massaro of England in a five-game thriller - 6-11, 11-9, 11-6, 8-11, 11-6.

Egypt's defending champion Raneem El Welily kept her title defence alive with a 3-0 win over England's Emily Whitlock.

She will now take on number 10 seed Alison Waters from England, who beat unseeded Egyptian Hania El Hammamy 3-2.

The other two quarter-finals, which were decided yesterday, will see England's Sarah-Jane Perry take on France's Camille Serme whilst Nour El Sherbini will face Nour El Tayeb in a match that sees two Egyptians go head-to-head.

In the men's draw, Miguel Angel Rodriguez of Colombia came out on top against fellow unseeded player Max Lee of Hong Kong in a 78-minute thriller, eventually winning 11-7, 11-13, 10-12, 11-5, 11-6.

"He was 2-1 up and mentally it is very tough to come back from that but I think I stayed positive," Rodriguez said after the match.

"I saw at the end of the fourth he was tired, so I had to come back stronger."

The Colombian now faces a tough match against soon-to-be world number one Mohamed Elshorbagy of Egpyt, who beat France's Mathieu Castagnet in three straight games.

As is the case in the women's quarter-finals, one of the men's quarter-finals will also see an Egyptian pair come up against each other after sixth seed Tarek Momen booked his place in the last eight with a 3-1 win over compatriot Ramy Ashour.

He will play Karim Abdel Gawad who secured his spot with a comfortable 3-0 win over Diego Elias of Peru.

The two other men's quarter-final matches, decided yesterday, will see Germany's Simon Rösner take on Egpyt's Marwan Elshorbagy and unseeded Australian Cameron Pilley come up against Egyptian number two seed Ali Farag.