Novak Djokovic has said that he found strength from within to come back from a set down against Juan Monaco at the Monte Carlo Masters.
The Serbian, struggling with an ankle injury, was on court for over two hours for the second day running, but managed to battle through for a place in the quarter-finals.
"It was another big test obviously, again a two-hour match," Djokovic told reporters. "Obviously I'm not physically out there feeling my best. Somehow feels that I always miss that half a step. But I'm trying. I'm fighting.
"After I lost the first set today, I tried to find that inner strength. I found it again. So that's a positive thing.
"Every day brings a new challenge and we'll see what happens tomorrow."
The world number one will play Jarkko Nieminen in the last eight after the Finn overcame Juan Martin del Potro 6-4 4-6 7-6[4].
