Rafael Nadal says now is the time to adopt a more aggressive approach as he prepares for the quarter-finals of the Australian Open. The world number one was below his sparkling best on Sunday as he dropped a set for the first time in the tournament before overcoming Diego Schwartzman 6-3 6-7 (4-7) 6-3 6-3.

Three times during the second set Nadal was a break up, but on each occasion the 24th seed hit back to force a tie-break, which he subsequently took to ensure the 2009 champion would have to dig deep. And Nadal did exactly that, pulling away in the final two sets to set up a last-eight meeting with Marin Cilic.

"Now we start the second week. Quarter-finals already," said Nadal. Now is the moment to make a step forward, to play again more aggressive.I know I'm going to have a tough opponent in front now, Cilic. I need to play aggressive and play well. That's what I'm going to try."

"Against Marin will be a tough one, but at the same time, it's a beautiful match to play against a great player. We know each other. We played a couple of times already.

"I know I need to play well. That's the real thing. I know I need to play well. That's what I'm going to try. I hope to be ready to make that happen. I'm very proud about the third and fourth set, because the situation was not easy for me, and I was able to hold my serve all the time, sometimes with saving tough moments."

"But I played with determination, and that's what I'm going to need, and I'm going to need to serve well. I'm going to need to play with more determination with my forehand in the next match. I am focusing on trying to make it" added the number one seed.