BEIJING (AP)—Top-ranked Novak Djokovic defeated Lukas Rosol of the Czech Republic 6-0, 6-3 in the first round of the China Open on Tuesday.

Djokovic's run of 100 weeks at the top of the ATP rankings is in danger this week from Rafael Nadal, who is scheduled to open against Santiago Giraldo of Colombia. Nadal will retake No. 1 if he reaches the final.

Djokovic will face Fernando Verdasco in the second round after the Spaniard beat Indian qualifier Somdev Devvarman 7-6 (6), 6-3.

Fifth-seeded Richard Gasquet of France beat Florian Mayer of Germany 6-3, 7-6 (2), and sixth-seeded Stanislas Wawrinka of Switzerland overcame Andreas Seppi of Italy 4-6, 6-3, 6-4.