Defending champion Roger Federer became the second high-profile casualty at the Madrid Open when he was beaten 6-4, 1-6, 6-2 by Japanese 14th seed Kei Nishikori in the third round on Thursday.
The Swiss second seed's surprise reverse follows Tuesday's shock defeat for world number one Novak Djokovic to unseeded Bulgarian Grigor Dimitrov.
Federer, 31, was playing his first tournament since taking a break following his loss against Rafa Nadal at the Indian Wells Masters in March.
It was the 23-year-old Nishikori's biggest win since he beat Serb Djokovic in the semi-finals in Basel in 2011.
Photograph: Gonzalo Arroyo Moreno/Getty Images
