Thursday 21 May 2015 21:57, UK
Top seed Madison Keys withdrew prior to her quarter-final in the Internationaux de Strasbourg on Thursday due to an elbow injury.
The American, who had rallied from a set and 5-0 down to beat Mirjana Lucic-Baroni the previous day, handed a walkover to opponent Kristina Mladenovic of France.
And second seed Jelena Jankovic was also forced out prematurely as she withdrew after dropping the first set of her last eight match 6-1 to Sloane Stephens.
Stephens will face third seed Sam Stosur in the last four after the Australian needed just over two hours to dispatch Croatia's Ajla Tomljanovic 6-4 3-6 6-4.
Meanwhile Mladenovic will face another Frenchwoman, Virginie Razzano, after Razzano came from behind to beat Elena Vesnina of Russia 4-6 6-1 6-1.
