Nadal, who has struggled with a wrist injury this season, dropped just two games in his first-round victory over Paolo Lorenzi and was similarly dominant in the opening set against Adrian Mannarino.
But he had to fight hard to take the second set, which lasted almost three times as long as the first, before finally wrapping up a 6-1 7-6 (8-6) success in rain-soaked in Beijing.
It was one of only two matches to be completed out of the four scheduled, with Grigor Dimitrov awaiting Nadal in the last eight after defeating Lucas Pouille.
The Bulgarian produced a gritty fightback to come from a set down in a 6-7 (3-7) 7-6 (7-0) 6-4 victory over the sixth seed.
But the weather halted Richard Gasquet’s contest with Pablo Carreno Busta when the Frenchman was leading 7-5 2-4.
The conditions also ensured Milos Raonic’s match against Malek Jaziri never made it on to court.