Top seed Gael Monfils suffered a final-set collapse as he was knocked out of the German Open at the quarter-final stage by fellow Frenchman and fifth seed Gilles Simon.
World number seven Monfils started the match in Hamburg as the clear favourite but was broken twice in the first set and despite levelling matters he suffered a calamitous decider, winning just four points as Simon ran out a 6-4 3-6 6-0 winner.
The result earned Simon a semi-final meeting with fourth seed Mikhail Youzhny after the Russian was forced to work hard before squeezing through against Croatia's Marin Cilic 4-6 6-3 7-6 (8/6).
Second seed Jurgen Melzer was surprised 6-3 2-6 6-4 by eighth seed Fernando Verdasco, who will next take on fellow Spaniard Nicolas Almagro after the third seed beat Germany's Florian Mayer 7-6 (7/5) 7-6 (7/3).
