Rising Swiss squash star Nicolas Mueller pulled off an impressive upset on the second day of action in the European Individual Championships in Poland when he beat experienced Spaniard Borja Golan to reach the men's semi-finals of the European Squash Federation event at Squash City in Warsaw.
The 21-year-old from Zurich battled for 44 minutes to overcome 3/4 seed Golan for the second time in three months, beating the former world No10 11-8, 11-8, 6-11, 11-1.
In his first appearance in the event's semi-finals, world No36 Mueller will face defending champion Thierry Lincou, ranked eight in the world.
The second-seeded Frenchman, who last month celebrated his 35th birthday, had to work hard to see off young compatriot Gregoire Marche - ultimately overcoming the 21-year-old 13-11, 11-7, 12-14, 11-8 in 71 minutes.
There will be French interest in the other semi-final where five-time champion Gregory Gaultier will take on Dutch champion Laurens Jan Anjema.
Top seed Gaultier, bidding to make the final for the eighth year in a row, defeated Mark Krajcsak 11-4, 11-6, 11-5 - thereby denying the top-ranked Hungarian a second successive semi-final appearance.
But Anjema almost failed to make his anticipated appearance in the last four. The world No15 from The Hague had to fight back from two games down against up-and-coming Frenchman Mathieu Castagnet - then saved a match ball at 9-10 in the fifth game before finally clinching his 3-11, 8-11, 11-2, 11-9, 12-10 quarter-final victory after 89 minutes.
The women's quarter- finals went according to the seedings, with 2009 champion Natalie Grinham edging closer to a second title. The 3/4 seed from the Netherlands, who missed last year's event following the birth of her first child, defeated newly-crowned German national champion Sina Wall 11-9, 11-5, 11-4.
Grinham will now face Emma Beddoes - but the second seed survived a close call with English compatriot Victoria Lust before beating her lower-ranked opponent 7-11, 9-11, 11-6, 12-10, 11-8.
Camille Serme, the top seed who is hoping to be part of a French double in Warsaw, took just 18 minutes to earn her place in the semis for the third time when she beat Dutch opponent Orla Noom 11-4, 11-3, 11-2.
Serme, the world No9 from Paris, now lines up against Manuela Manetta following the Italian's 11-8, 11-8, 11-7 defeat of Austrian Birgit Coufal.
RESULTS: European Individual Squash Championships, Warsaw, Poland
Men's 2nd round:
[1] Gregory Gaultier (FRA) bt [9/16] Bart Ravelli (NED) 11-6, 11-2, 11-6 (26m)
[5/8] Mark Krajcsak (HUN) bt [9/16] Jens Schoor (GER) 11-6, 11-3, 11-5 (29m)
[5/8] Mathieu Castagnet (FRA) bt [9/16] Charles Sharpes (ENG) 9-11, 11-8, 11-5, 12-10 (88m)
[3/4] Laurens Jan Anjema (NED) bt Roman Svec (CZE) 11-2, 11-5, 11-4 (21m)
[3/4] Borja Golan (ESP) bt [9/16] Piedro Schweertman (NED) 11-9, 11-7, 13-11 (54m)
[5/8] Nicolas Mueller (SUI) bt Nathan Lake (ENG) 11-4, 11-6, 11-5 (28m)
[5/8] Gregoire Marche (FRA) bt [9/16] Aqeel Rehman (AUT) 4-11, 11-2, 11-2, 11-7 (48m)
[2] Thierry Lincou (FRA) bt Manuel Fistonic (CRO) 11-4, 11-5, 11-6 (23m)
Quarter-finals:
[1] Gregory Gaultier (FRA) bt [5/8] Mark Krajcsak (HUN) 11-4, 11-6, 11-5 (35m)
[3/4] Laurens Jan Anjema (NED) bt [5/8] Mathieu Castagnet (FRA) 3-11, 8-11, 11-2, 11-9, 12-10 (89m)
[5/8] Nicolas Mueller (SUI) bt [3/4] Borja Golan (ESP) 11-8, 11-8, 6-11, 11-1 (44m)
[2] Thierry Lincou (FRA) bt [5/8] Gregoire Marche (FRA) 13-11, 11-7, 12-14, 11-8 (71m)
Women's quarter-finals:
[1] Camille Serme (FRA) bt [5/8] Orla Noom (NED) 11-4, 11-3, 11-2 (18m)
[3/4] Manuela Manetta (ITA) bt [5/8] Birgit Coufal (AUT) 11-8, 11-8, 11-7 (29m)
[3/4] Natalie Grinham (NED) bt [5/8] Sina Wall (GER) 11-9, 11-5, 11-4 (23m)
[2] Emma Beddoes (ENG) bt [5/8] Victoria Lust (ENG) 7-11, 9-11, 11-6, 12-10, 11-8 (62m)
Men's semi-final line-up:
[1] Gregory Gaultier (FRA) v [3/4] Laurens Jan Anjema (NED)
[2] Thierry Lincou (FRA) v [5/8] Nicolas Mueller (SUI)
Women's semi-final line-up:
[1] Camille Serme (FRA) v [3/4] Manuela Manetta (ITA)
[2] Emma Beddoes (ENG) v [3/4] Natalie Grinham (NED)