Dutchman Laurens Jan Anjema upset eighth seed David Palmer in the second round of the Delaware Investments US Open to record his career-first Tour victory over the Australian veteran in the fifth PSA World Series squash event of the year at the Daskalakis Athletic Center at Drexel University in Philadelphia.

The 28-year-old from The Hague and fellow non-seed Mohd Azlan Iskandar, of Malaysia, will join Frenchman Thierry Lincou, Egyptian pair Amr Shabana and Mohamed El Shorbagy, together with English trio Nick Matthew, James Willstrop and Peter Barker in the quarter-finals of the long-established event which is being staged in Philadelphia for the first time since 1993.

Anjema beat Palmer in a play-off match in the World Team Championship in Germany in August, but the 35-year-old Aussie had always had the edge over the Dutchman in PSA encounters.

Palmer, ranked eight in the world, controlled proceedings to take the opening game, looking set to continue his Tour run. But, from 2-5 down in the second, Anjema began to take the upper hand. After winning the second, the Dutchman romped to a 7-0 lead in the third en-route to moving 2/1 ahead - and built up a 7-2 lead in the fourth.

But the vastly-experienced Palmer dug deep, and slowly brought the score back to seven-all. The Aussie saved one match-ball at 10-9 before Anjema chanced his arm to hit the nick with the second to raise both arms in celebration of his long-awaited 7-11, 11-5, 11-3, 11-9 victory after 76 minutes.

"I just tried to play my own game and not panic after losing the first," Anjema told event website www.usopensquash.com afterwards. "I was pleased to have recovered so well, but it was nerve-wracking at the end, getting those last five points.

"He was one of my idols when I was growing up, so to beat him for the first time in PSA is pretty special," added the world No12. "It was a mental victory tonight, I decided to take a risk at the end and thankfully it came off. I hope I can be a bit steadier for the whole match next round."

Anjema will now face fourth seed Amr Shabana. The 2009 champion from Egypt repeated his victory over fellow left-hander Adrian Grant in a rerun of his encounter with the Englishman at the quarter-final stage of the British Grand Prix a week ago. The Egyptian won that one in three close games, Grant threatening to take each one - but this time the Londoner did more than threaten, as he took the lead 11-6.

Thereafter, however, Shabana showed why he is a four-time world champion. Controlling the play without looking overly troubled or hurried, Shabana took the next three games to claim his fourth successive quarter-final berth in the event following his 6-11, 11-6, 11-5, 11-7 win.

"I just played him a few days ago, and he upped his pace right from the start which took me a little by surprise," said 32-year-old Shabana. "He has good touch too, so it's tricky to hold him off, so it was good to be able to take those three games.

"I'm just trying to stay healthy and listen to my body. I'll take the rest day tomorrow and hopefully be ready for the rest of the tournament."

Younger compatriot Mohamed El Shorbagy also booked his place in the last eight with an 11-2, 11-6, 8-11, 11-4 win over rising English star Tom Richards.

The 20-year-old No7 seed will now face top seed Nick Matthew, the world number one from England who eased to an 11-8, 11-3, 11-5 victory over tall Egyptian Omar Mosaad.

The unseeded 23-year-old from Cairo fully tested the favourite in the opening game, holding a few points' lead before Matthew finally closed it out with some typically solid play in the final few points.

"The first game was long and drawn out - he came with a strategy and stuck to it well," said Matthew. "It wasn't physically demanding as such, more a mental battle with lots of slow rallies. I was a bit sluggish at the start and left too many things hanging out on his forehand. I managed to claw back the few points lead he had and was more comfortable after that."

National team-mates and career-long rivals Peter Barker and James Willstrop will line up in a clash which will guarantee an English semi-finalist. Fifth seed Barker despatched Egyptian Hisham Mohamed Ashour 11-9, 11-6, 11-4, while Willstrop, the No3 seed, brushed aside fellow countryman Daryl Selby, the reigning British national champion, 11-7, 11-5, 11-6.

Clearly hampered by an injury midway through the second game, Ashour saw out the match. Barker later paid tribute to his opponent in carrying on where many would have stopped.

Veteran Frenchman Thierry Lincou earned his first appearance in the last eight of a PSA World Series event this year following his 7-11, 11-6, 11-4, 13-11 victory over Colombian Miguel Angel Rodriguez.

The 25-year-old from Bogota had earned the nickname 'The Cat' after his spectacular upset over higher-ranked Egyptian Mohd Ali Anwar Reda in the previous round.

But after dropping the first game, sixth seed Lincou restricted the Colombian's opportunities by pinning him to the back corners, and opened up a 2/1 lead.

Rodriguez managed to eke out an advantage in the fourth though, and Lincou had to save five game balls before finally taking the match on his own first opportunity, putting in a clinging drop-shot that Rodriguez's racket could only brush into the floor.

"He's a very unusual opponent," said a relieved Frenchman. "So fast and such an exciting style of play. You think you've hit a winner and it comes back, you have to start all over again, and you have to be alert all the time, on every shot. I really had to use my experience to counter him."

Lincou will take on Malaysian Mohd Azlan Iskandar, the 11-6, 11-7, 11-3 winner over Swiss qualifier Nicolas Mueller.

"Hats off to him, he's improved a lot in the last year and is beginning to really push the top guys," Iskandar said of his opponent. "But I went in with a game plan and stuck to it."

RESULTS: PSA World Series Delaware Investments US Open, Philadelphia, USA

2nd round:
[1] Nick Matthew (ENG) bt Omar Mosaad (EGY) 11-8, 11-3, 11-5 (49m)
[7] Mohamed El Shorbagy (EGY) bt Tom Richards (ENG) 11-2, 11-6, 8-11, 11-4 (53m)
[5] Peter Barker (ENG) bt Hisham Mohamed Ashour (EGY) 11-9, 11-6, 11-4 (40m)
[3] James Willstrop (ENG) bt Daryl Selby (ENG) 11-7, 11-5, 11-6 (48m)
[4] Amr Shabana (EGY) bt Adrian Grant (ENG) 6-11, 11-6, 11-5, 11-7 (51m)
Laurens Jan Anjema (NED) bt [8] David Palmer (AUS) 7-11, 11-5, 11-3, 11-9 (76m)
[6] Thierry Lincou (FRA) bt Miguel Angel Rodriguez (COL) 7-11, 11-6, 11-4, 13-11 (69m)
Mohd Azlan Iskandar (MAS) bt [Q] Nicolas Mueller (SUI) 11-6, 11-7, 11-3 (42m)

Quarter-final line-up:
[1] Nick Matthew (ENG) v [7] Mohamed El Shorbagy (EGY)
[3] James Willstrop (ENG) v [5] Peter Barker (ENG)
[4] Amr Shabana (EGY) v Laurens Jan Anjema (NED)
Mohd Azlan Iskandar (MAS) v [6] Thierry Lincou (FRA)

More details on the Official Website: www.usopensquash.com

For all the latest Tour news: www.psaworldtour.com