PARIS, April 18 (Xinhua) -- Novak Djokovic fought back his suspect right ankle injury and challenge from Juan Monaco of Argentina, winning 4-6, 6-2, 6-2 to enter the quarter-finals of the Monte Carlo Masters on Thursday.

Spanish Rafael Nadal met little trouble to cruise into the top 8 by beating German Philipp Kohlschreiber 6-2, 6-4, to set up a quarter-final meet with Grigor Dimitrov of Bulgaria who defeated Marin Cilic of Croatia 7-5, 6-4.

Meanwhhile, second-seeded Andy Murray of Britain had a hard time as he faced Swiss Stanislas Wawrinka, losing 6-1, 6-2 in a stroke.

Top seed Djokovic losing the first set, partly due to his injury which threatened to keep him from the event. The Serb only bounced back with determination to take the next two round for a sweet comeback.

Nadal, who is seeking for his ninth trophy in the Masters, won his 44th match in a row at Monte Carlo.

In other matches on Thursday, Jarkko Nieminen beat Juan Martmn Del Potro 6-4, 4-6, 7-6 (7-4), Fabio Fognini beat Tomas Berdych 6- 4, 6-2, Richard Gasquet beat Marin Cilic 7-5, 6-4, Grigor Dimitrov beat Florian Mayer 6-2, 6-4, and Jo-Wilfried Tsonga beat Jurgen Melzer 6-3, 6-0.