New Yorker Haley Mendez boosted US interest in the last 16 of the WSF Women's World Junior Individual Squash Championship in Boston, USA, after producing the biggest upset on day two of the World Squash Federation championship at Harvard University.

The unseeded 17-year-old ousted top Australian junior Tamika Saxby, a 5/8 seed, 11-8, 12-10, 11-9 - and will now face Egypt's Salma Hany, a 9/16 seed, for a place in the quarter-finals.

"I'm so proud of her," a delighted US National Coach Natalie Grainger told the official website www.worldsquash.org/worldjuniors2011 after the stunning third round win. "She's transformed herself with so much hard work, and this is a great reward for that," added the former world number one.

Mendez could hardly contain her delight at making the fourth round: "I'm in the last sixteen?" asked the teenager.

"I never felt under a lot of pressure and always felt I was in control," explained Mendez. "I remember being an extra on the team two years ago in Chennai - and I thought it was so cool getting a couple of minutes on court to practice with Tamika, so to actually beat her in this event two years later is just great."

Defending champion Amanda Sobhy and 3/4 seed Olivia Blatchford also delighted their local supporters with straightforward third round victories. Sobhy, the 17-year-old No2 seed from New York, despatched Hong Kong 15-year-old Ho Tze-Lok 11-2, 11-2, 11-2 in just 14 minutes, while Blatchford also defeated a Hong Kong opponent Ka-Yi Lee 11-9, 12-10, 11-8.

"I'm just happy to get into the next round," admitted 18-year-old Blatchford, also from New York. "She played really well, and played differently from how I expected, taking it to the front a lot. I was a bit late in reading some of her shots, but managed to get through so it's good still to be in for tomorrow."

But it was Welsh star Tesni Evans who survived the toughest match of the day, beating Canada's Danielle Letourneau 11-9, 8-11, 12-10, 11-8 in 45 minutes.

"I was a bit loose," admitted Evans, the Welsh number one seeded in the 9/16 group. "I'd never played her before and was surprised by how good she was, but you just have to dig in when you're not getting the ball tight."

Event favourite Nour El Tayeb led a group of six Egyptians through to the last 16 with an assured 11-1, 11-3, 11-2 victory over Malaysian Celine Yeap.

El Tayeb, the 18-year-old from Cairo who is ranked 17 in the WISPA world rankings, will now face leading Indian Anaka Alankamony, the Asian Junior Champion who beat Canada's Alix Younger 11-8, 11-4, 11-8.

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

3rd round:
[1] Nour El Tayeb (EGY) bt Celine Yeap (MAS) 11-1, 11-3, 11-2 (15m)
[9/16] Anaka Alankamony (IND) bt Alix Younger (CAN) 11-8, 11-4, 11-8 (21m)
Haley Mendez (USA) bt [5/8] Tamika Saxby (AUS) 11-8, 12-10, 11-9 (33m)
[9/16] Salma Hany (EGY) bt Vanessa Raj (MAS) w/o
[3/4] Olivia Blatchford (USA) bt Ka-Yi Lee (HKG) 11-9, 12-10, 11-8 (27m)
[9/16] Melissa Alves (FRA) bt Caroline Sayegh (GER) 11-6, 3-11, 11-5, 11-6 (42m)
[5/8] Emily Whitlock (ENG) bt Sabrina Sobhy (USA) 11-5, 11-1, 11-3 (29m)
[9/16] Megan Craig (NZL) bt Maria Elena Ubina (USA) 11-6, 11-5, 11-1 (20m)
[9/16] Tesni Evans (WAL) bt Danielle Letourneau (CAN) 11-9, 8-11, 12-10, 11-8 (45m)
[5/8] Nouran El Torky (EGY) bt Chloe Pearson (ENG) 11-0, 11-1, 11-4 (15m)
[9/16] Ho Ka Po (HKG) bt Sue Ann Yong (MAS) 11-6, 11-9, 11-5 (30m)
[3/4] Nour El Sherbini (EGY) bt Aparajitha Balamurukan (IND) 11-6, 11-5, 11-6 (20m)
Mariam Ibrahim Metwally (EGY) bt Risa Sugimoto (JPN) 11-5, 11-4, 11-3 (19m)
[5/8] Kanzy Emad El-Defrawy (EGY) bt Danielle Fourie (NZL) 11-3, 11-6, 11-4 (30m)
[9/16] Tan Yan Xin (MAS) bt Steffi Rosner (GER) 11-3, 11-3, 11-3 (17m)
[2] Amanda Sobhy (USA) bt Ho Tze-Lok (HKG) 11-2, 11-2, 11-2 (14m)

4th round line-up:
[1] Nour El Tayeb (EGY) v [9/16] Anaka Alankamony (IND)
Haley Mendez (USA) v [9/16] Salma Hany (EGY)
[3/4] Olivia Blatchford (USA) v [9/16] Melissa Alves (FRA)
[5/8] Emily Whitlock (ENG) v [9/16] Megan Craig (NZL)
[5/8] Nouran El Torky (EGY) v [9/16] Tesni Evans (WAL)
[3/4] Nour El Sherbini (EGY) v [9/16] Ho Ka Po (HKG)
[5/8] Kanzy Emad El-Defrawy (EGY) v Mariam Ibrahim Metwally (EGY)
[2] Amanda Sobhy (USA) v [9/16] Tan Yan Xin (MAS)

Official website: www.worldsquash.org/worldjuniors2011