Davydenko needed just 56 minutes to book his quarter-final place
Novak Djokovic eased into the last eight of the China Open with a 6-3 6-0 win over fellow Serb Viktor Troicki.
The 22-year-old second seed broke Troicki to go up 5-3 in the first set and then won the next seven games to see off his compatriot in 61 minutes.
He will now play Fernando Verdasco who recorded a 7-5 6-4 win over fellow Spaniard Juan Carlos Ferrero.
Fourth seed Nikolay Davydenko beat Germany's Philipp Kohlschreiber 6-1 6-0 to also make the quarter-finals.
The 28-year-old Russian took just 56 minutes to complete his win, dropping just three points on his own serve.
Davydenko, the world number eight, broke his opponent's serve six times.
He will face eighth seed Marin Cilic in the last eight after the Croatian came through a fluctuating match with Julien Benneteau, winning 6-2 2-6 6-0.
Cilic, ranked 15th in the world, cruised through the first set after breaking in the opening game.
Benneteau came back strongly in the second set to level the match but could not sustain that form in the decider, failing to win a single point on Cilic's serve.