Novak Djokovic qualified for the China Open final on Monday after Daniil Medvedev defaulted in the second set, when a ball that came off the Russian's racquet hit a spectator.
A man sitting in the stands behind Medvedev's side of the court was seen holding his face and escorted out of his seat after being hit, as Djokovic was serving for the match with the score at 7-5, 5-3.
Djokovic will play Alex de Minaur for the title on Tuesday in Beijing.