Quarter-finals:
[6] Julian Illingworth (USA) bt [1] Alex Gough (WAL) 9-11, 11-6, 11-9, 11-9
[4] Renan Lavigne (FRA) bt [8] Mark Krajcsak (HUN) 11-7, 11-8, 11-9
[7] Yasser El Halaby (EGY) bt [3] Alister Walker (ENG) 11-8, 11-9, 11-7
[2] Cameron Pilley (AUS) bt [5] Shawn Delierre (CAN) 11-8, 11-4, 11-0
US champion Julian Illingworth defeated top-seeded Welshman Alex Gough in the quarter-finals of the Berkshire Open to produce the best win of his professional career in the $20,000 PSA Tour squash event in its fourth year at Williams College in Williamstown, USA.
Illingworth, the sixth seed from Portland, recovered from a game down to topple the world No 23 9-11, 11-6, 11-9, 11-9.
The 23-year-old 2006 Yale graduate will now face fourth-seeded Frenchman Renan Lavigne, who beat Hungary's Mark Krajcsak 11-7, 11-8, 11-9.
Egyptian Yasser El Halaby also produced a popular upset. The four-time collegiate champion, from Cairo, defeated Alister Walker, the fourth seed from England, 11-8, 11-9, 11-7.
The No7 seed will now take on reigning champion Cameron Pilley, the No2 seed from Australia who demolished Canadian Shawn Delierre 11-8, 11-4, 11-0 in just under 25 minutes.
Semi-final line-up:
[6] Julian Illingworth (USA) v [4] Renan Lavigne (FRA)
[2] Cameron Pilley (AUS) v [7] Yasser El Halaby (EGY)