Farag was on an 18-match unbeaten run in Chicago following his triumph at the 2020 tournament, with that run also including the 2018-2019 and 2020-2021 World Championships held there.

After close first and second games which left the match level, Farag surrendered three game points in the third game to hand his opponent a crucial lead.

World number seven ElShorbagy went on to secure a 6-11, 11-9, 12-10, 11-7 victory.

"It’s always tough playing Ali, it’s always tense, but I just tried to keep my composure, we were both arguing but I think it’s part of the game, we’re in such a small space, interference will always happen but Ali is such a great player and I respect him a lot," said ElShorbagy.

"He's a two-time world champion and has been world number for many months, and I know he’s losing it to Paul [Coll], but he’ll be determined to get it back."

ElShorbagy was runner-up at the Windy City Open in 2017 and 2018 and will face compatriot Youssef Ibrahim in the semi-finals.

Ibrahim made it to his first Professional Squash Association Platinum event semi-final after beating Spain's Iker Pajares Bernabeu 11-5, 11-4, 11-6 in 34 minutes.

The world number 17 ran away with the match against Pajares, who was appearing in his maiden quarter-final at this level.

In the women's tournmanet, the world's number one and three, Nour El Sherbini and Hania El Hammamy, set up a semi-final meeting after taking respective wins against fellow Egyptians Rowan Elaraby and Salma Hany.

El Sherbini dispatched Elaraby 11-7, 11-3, 11-2 in just 29 minutes.

El Hammamy also recorded a comfortable win, 11-8, 11-8, 11-5, to advance to the semi-finals for the first time.

"I’m really happy to beat Salma in three, she’s such a dangerous opponent and is very hard to play, very tricky," said El Hammamy.