Nadal, Djokovic advance at Monte Carlo Masters Novak Djokovic of Serbia returns the ball to Alexandr Dolgopolov of Ukraine during the Mont...

Nadal, Djokovic advance at Monte Carlo Masters

Novak Djokovic of Serbia returns the ball to Alexandr Dolgopolov of Ukraine during the Monte Carlo Masters in Monaco April 19, 2012. (Xinhua/Reuters Photo)

Rafael Nadal of Spain returns the ball to Mikhail Kukushkin of Kazakhstan during the Monte Carlo Masters in Monaco April 19, 2012.(Xinhua/Reuters Photo)

Novak Djokovic of Serbia reacts after defeating Alexandr Dolgopolov of Ukraine during the Monte Carlo Masters in Monaco April 19, 2012. (Xinhua/Reuters Photo)

Rafael Nadal of Spain serves the ball to Mikhail Kukushkin of Kazakhstan during the Monte Carlo Masters in Monaco April 19, 2012. (Xinhua/Reuters Photo)

Novak Djokovic and Rafael Nadal advance at the Monte Carlo Masters in Monaco April 19, 2012.