Top seed Novak Djokovic overcame a second set blip to beat Spaniard Fernando Verdasco in three and reach the quarter-finals of the China Open in Beijing, keeping alive his hopes of clinging on to his world number one ranking.
The defending champion, aiming for his fourth China Open title in five years after missing the 2011 tournament through injury, will lose the top spot next week if Spaniard Rafa Nadal reaches the final in Beijing.
In the quarter-finals, the Serb will face American Sam Querrey, who caused an upset by beating sixth-seed Swiss Stanislas Wawrinka.
Reigning Australian Open champion Djokovic is without a title since the Monte Carlo Masters in April.
Meanwhile in the women's draw there have been wins for Serena Williams, Agnieszka Radwanska and Caroline Wozniacki.