Emily Whitlock, a 17-year-old from England in her maiden appearance in the WSF Women's World Junior Individual Squash Championship, stormed into the semi-finals of the World Squash Federation championship in Boston, USA, after upsetting home hope Olivia Blatchford at Harvard University.

After surviving a tough four-game last 16 round match against New Zealander Megan Craig, 5/8 seed Whitlock defeated 3/4 seed Blatchford, an 18-year-old from New York in her fourth appearance in the championship, 11-8, 11-8, 11-7 in 33 minutes.

"It didn't feel like a quarter," Whitlock told the official website www.worldsquash.org/worldjuniors2011 afterwards. "All I wanted to do was reach my seeded position, and after yesterday my confidence was really down.

"But I played well there. I haven't even won but I'm so happy," added the recently-crowned European Junior champion from Colwyn Bay in Wales.

Whitlock will now face Egypt's Nour El Tayeb, the 18-year-old from Cairo who is seeded to reach the final for the third year in a row - but expected to win the title for the first time.

El Tayeb, ranked 18 in the world, saw off compatriot Salma Hany, an 18-year-old 9/16 seed from Giza, 11-8, 11-0, 11-4.

"I know Salma's game, so I was less nervous before the start of this match," said the favourite. "It was never an easy match though, even in the second there were still tough rallies, but I was pleased with how I played and I'm happy to be in the semi-finals.

"I was surprised that Emily beat Olivia - but she's a good player and I know I'll have to play well again to counter what she throws at me. I'm looking forward to it."

The other semi-final will pitch 2010 champion Amanda Sobhy against the 2009 winner Nour El Sherbini. Sobhy, the 18-year-old from New York who last year became the first US squash player in history to win a world singles title, defeated unseeded 14-year-old Egyptian Mariam Ibrahim Metwally 11-6, 11-3, 11-5.

"I'm feeling pretty good, trying to keep the pace high and volleying everything I can, and I'm seeing the ball well on here too - which is usually a problem for me on glass courts," explained second seed Sobhy.

"The home crowd gives you a boost too, it makes you want to give your best and picks you up if anything goes wrong. All the Egyptians are good - but she's very young and I knew that if I got on top early and started to dominate I could break her mentally.

"I'm glad it's my last year though - I wouldn't want to face her in two years' time!"

El Sherbini stunned the squash world two years ago when she won the title in India aged just 13 - becoming youngest world champion ever.

The 3/4 seed beat fellow Egyptian Nouran El Torky, a 5/8 seed, 11-8, 11-3, 11-4.

"We know each other's games well and it's usually close, so I knew I had to concentrate to do well in this match," said the 15-year-old from Alexandria. "Winning the first was very important and after I'd done that it gave me confidence to go for more shots in the second and third.

"I thought I played well and I'm happy with my performance today. I'm looking forward to the semi-final and hope I can play well again."

RESULTS: WSF Women's World Junior Individual Squash Championship, Boston, USA

Quarter-finals:
[1] Nour El Tayeb (EGY) bt [9/16] Salma Hany (EGY) 11-8, 11-0, 11-4 (30m)
[5/8] Emily Whitlock (ENG) bt [3/4] Olivia Blatchford (USA) 11-8, 11-8, 11-7 (33m)
[3/4] Nour El Sherbini (EGY) bt [5/8] Nouran El Torky (EGY) 11-8, 11-3, 11-4 (25m)
[2] Amanda Sobhy (USA) bt Mariam Ibrahim Metwally (EGY) 11-6, 11-3, 11-5 (24m)

Semi-final line-up:
[1] Nour El Tayeb (EGY) v [5/8] Emily Whitlock (ENG)
[2] Amanda Sobhy (USA) v [3/4] Nour El Sherbini (EGY)

Official website: www.worldsquash.org/worldjuniors2011