Former world number one Rafael Nadal reached the Rio Open semi-finals without even hitting a ball Friday as Aleksandr Dolgopolov withdrew injured from their last-eight tie. Nadal is playing at the low-key clay court event in a bid to find his form ahead of a tilt at an unprecedented 10th French Open crown in June.

The 29-year-old Spaniard has dropped to number five in the world after an injury-hit 2015 and suffered a shock semi-final defeat to Austria's Dominic Thiem in the semi-finals last week at Buenos Aires, where he was defending champion.

Ukraine's Dolgopolov was forced to withdraw due to a right shoulder injury. Nadal will next play in Saturday's semi-finals against Uruguay's Pablo Cuevas, who defeated Argentina's Federico Delbonis 6-4, 7-6 (7/4).