The Egyptian siblings became the first brothers in history to contest the final of the prestigious event in 2017, with Mohamed winning the title after a five-game battle.

Another five-game clash unfolded today at the Khalifa International Tennis and Squash Complex.

Marwan claimed the opening game 11-6, as he looked to improve on his record of just three wins in 17 matches against his brother.

The response was immediate from Mohamed, as he took the second 11-2.

Marwan retook the lead in the next game, only for Mohamed to level the score again and take the match into a decider.

Marwan held his nerve in the final game to ultimately seal an 11-6, 2-11, 11-6, 3-11, 11-8 victory.

The result means there is no previous world champion remaining in the draw.

Marwan praised the influence of his coach Haitham Effat and former world champion Nick Matthew, having started working with the Briton after his retirement this summer.

"I have so much experience in my corner here, in Haitham and Nick and the way they speak to me between games, it motivates me and it pushes me," Marwan said.

"It was five games in less than an hour, but I know it was really tough mentally for me - Mohamed is one of the most experienced players in the draw.

"He has played against so many different generations, so I knew it was going to be really tough mentally much more than physically.

"At the end it was all mental, and I gave it everything I had."

Marwan will face Paul Coll in the semi-finals, after fourth seed won 11-8, 11-9, 11-6 against Egypt's Zahed Salem.

The victory saw Coll become the first New Zealand player since Ross Norman in 1988 to reach the semi-finals of the men's World Championship.

Tournament second seed Tarek Momen will feature in the second semi-final, after the Egyptian beat Peru's Diego Elias 11-6, 13-11, 11-6.

He will now face Germany's Simon Rösner for a place in the final.

Rösner was a 14-12, 11-6, 11-3 winner against England's James Willstrop, the 2010 runner-up.