Pajeres secured his place in the third round in Illinois via a tenacious performance which saw him come back from two games versus the world number six.

The Spaniard triumphed 6-11, 8-11, 11-7, 11-8, 13-11.

Pajeres, who was forced to retire from last week's Squash on Fire Open, had three match points in the deciding game before Elías quickly rallied back to force a tiebreak.

The underdog was able to take the next point prior to a controversial decision from the referee where they ruled Elías' retrieval as a double bounce, handing the win to Pajeres.

"I’m over the moon, it’s the best win of my career," said Pajares.

"I wasn’t expecting that, I’ve been in the US for three weeks and I woke up this morning with my body not feeling great and I was just thinking about home.

"I don’t know what happened, I went 2-0 down then just carried on. 

"I saw he started to get a little tired, so I pushed a bit more."

Pajares will play Mexico’s Cesar Salazar in the third round after he beat Hong Kong’s Tsz Fung Yip in straight games.

The American men's number one Todd Harrity is due to appear in the third round of the Professional Squash Association World Tour Platinum event for the first time in his career after recording an 11-2, 9-11, 11-8, 13-11 win against England's Declan James.

He will face two-time runner-up Marwan ElShorbagy of Egypt next.

In the women’s event, unseeded Belgian Nele Gilis got the better of Egypt's 2018 champion Nour El Tayeb in a gripping contest - winning 11-9, 11-6, 2-11, 8-11, 11-9 in 60 minutes.

El Tayeb was playing her third tournament since returning from a 14-month hiatus due to the birth of her daughter.

Gilis will take on England’s Georgina Kennedy next following a 3-1 win over American number two Olivia Fiechter.