German ace Simon Rosner will meet top seed Ramy Ashour in the quarter-finals of the Davenport North American Open after winning a battle of the giants against No8 seed Omar Mosaad in the second round of the PSA World Series event in Virginia.
With Rosner 6ft 3in tall, and Egyptian Mosaad an inch taller, there was little room to spare on court at the Westwood Club in Richmond.
Rosner (pictured in action with Mosaad) produced a performance of enormous physical commitment and tactical intelligence to deliver the first major upset in this second PSA World Series tournament of the year.
With two such tall athletes, there were frequent collisions in mid-court caused by access problems to the ball, mainly on the left-hand wall.
The world No9 from Cairo used his powerful frame to good effect with a solid opening game, but Rosner - ranked seven places below - hit back to take the next two.
As the seven-time German national champion attempted to close in on the fourth, Mosaad finished strongly to take the match into a fifth game decider.
Rosner started strongly and kept in front all the way, fending off a desperate late revival by the Egyptian to book his place in Thursday's quarter-finals.
Rosner's tactics worked soundly. His straight lines were accurate, his crosscourts forced a heavily-built opponent to twist and turn, and his drop shots were effective.
The blockages and clashes caused a tension throughout the match, but the frown disappeared and a huge smile crossed his face as a delighted Rosner finally clinched victory after 82 minutes - his first over the higher-ranked Egyptian in four meetings since 2007.
"I lost to Omar in Mexico in November, and that finished 11-9 in the fifth, so I knew what to expect today," said the 25-year-old from Paderborn. "He's a big guy to get round and there were a lot of traffic jams in the middle of the court.
"It's always a good feeling to beat a seeded player and reach the quarter-finals of a tournament like this."
Rosner faces a tough assignment against Ashour, who was in mesmerizing form as he beat Australian Cameron Pilley.
Ashour won the match in straight games but Pilley had the opportunity to win the third when he held game ball at 10-8. But the Egyptian maestro finished strongly to take the match.
The world number one and world champion produced moments of breath-taking genius from various parts of the court, but Pilley was equally impressive with some incredible pick-ups and stunning winners.
In the end, the Australian will reflect on a few tins too many at crucial times.
A delighted Ashour said: "Even though this is my job, you can't think like that. You have to love the game, and respect every part of it. I love coming here to Richmond and playing in front of this great crowd."
Ashour's right leg was encased in a surgical stocking but it did not seem to impair his phenomenal movement.
He said: "It's just a precaution. No single player is ever 100 per cent fit. We all have little niggles and have to deal with a lot of small injuries all the time. That's just part of the game and you have to deal with it."
However, Darwish later withdrew because of a calf injury, giving Willstrop a rest day and a walkover to the semi-finals.
Matthew said: "Chris and I share the same coach, David Pearson, and I discussed tactics with him when he was drawn against Tarek. But it's one thing to offer advice and another to follow it yourself.
"The scoreline doesn't do Tarek justice. It was a very hard-fought match and it's not easy to get a three-love against such a good player.
"I was pleased for Chris last night. I told him not be content with just qualifying for the main draw and he took it on board.
"With so many important tournaments in the States, it's good to see a US player contributing so much and engaging the crowd as he did last night. It's certainly good for the game," added the world No2 from Sheffield.
NAO action image by Dan Bogosh
 Ramy Ashour (EGY) bt Cameron Pilley (AUS) 11-8, 11-6, 12-10 (42m)
Simon Rosner (GER) bt  Omar Mosaad (EGY) 4-11, 11-8, 11-8, 9-11, 11-9 (82m)
 Karim Darwish (EGY) bt Hisham Mohd Ashour (EGY) 7-11, 11-5, 9-11, 11-8, 11-2 (45m)
 James Willstrop (ENG) bt Miguel Angel Rodriguez (COL) 11-7, 11-7, 11-1 (39m)
 Gregory Gaultier (FRA) bt Adrian Grant (ENG) 11-4, 11-4, 11-6 (40m)
 Amr Shabana (EGY) bt Karim Abdel Gawad (EGY) 11-9, 9-11, 11-3, 11-8 (51m)
 Peter Barker (ENG) bt Olli Tuominen (FIN) 11-4, 11-6, 9-11, 11-4 (55m)
 Nick Matthew (ENG) bt Tarek Momen (EGY) 11-7, 11-8, 11-6 (44m)
 Ramy Ashour (EGY) v Simon Rosner (GER)
 James Willstrop (ENG) bt  Karim Darwish (EGY) w/o
 Gregory Gaultier (FRA) v  Amr Shabana (EGY)
 Nick Matthew (ENG) v  Peter Barker (ENG)