Kristina Mladenovic is out of the Samsung Open in Lugano, Switzerland, after retiring with a back injury while a set and a break down against German qualifier Tamara Korpatsch.
Mladenovic, the world No. 19, was the top seed for the tournament in Switzerland, but she was forced to call it quits when 7-6, 3-2 down in the second set.
Korpatsch, who is 157 places below Mladenovic in the world rankings, saved a break point in the opening game of the match, but was able to more than match her more established opponent as the first set wore on, eventually taking it by tiebreak before Mladenovic's decision to retire in the second set.
There were other shocks elsewhere, as fourth seed Anett Kontaveit squandered a set lead to Vera Lapko, while the fifth seed, Svetlana Kuznetsova, also crashed out in defeat to Mona Barthel.