Rafael Nadal insisted he is not "obsessed" in his quest for further grand slam glory after the 20-time major champion moved through to the Australian Open quarter-finals. 

Nadal advanced to the last eight of the tournament for the 13th time in his illustrious career following Monday's dominant 6-3 6-4 6-2 victory over 16th seed Fabio Fognini.

World number two Nadal is bidding to claim a record 21st slam crown, while the Spanish star is also looking to become the first man in the Open Era to win each of the four majors twice.

As Nadal looks ahead to a showdown with fifth seed Stefanos Tsitsipas, he discussed his motivations, having won everything on offer on the ATP Tour.

"I play tennis. I like tennis," the 34-year-old said. "I like what I am doing. That's the main thing. 

"Of course I am very motivated to win grand slams and to play in the most important events of the year. No doubt about that.

"The only thing that I said is I have never been obsessed to try to be the best or to try to – no, I just did my way. That worked for me.

"I think the ambition is important, to have an ambition, but a healthy ambition. If you have too much ambition then you can be frustrated when you are not able to achieve all the things that you wanted.

"I never approached the sport and my career that way. That's it. I enjoy, I give my best always. I try to compete at my highest standards every day. Sometimes the highest standards are 60 per cent, sometimes they are 100 per cent. But I just try to give my best throughout my career, and that's it.

"For me the main thing is come back home with personal satisfaction that you gave it everything. That's what gives me happiness and makes me stay calm."

Nadal was under an injury cloud heading into the year's first grand slam due to a back problem which forced him to sit out Spain's ATP Cup campaign in Melbourne.

But the 2009 Australian Open champion has looked comfortable at Melbourne Park, where he is yet to drop a set.

"I played first set without a doubt [against Fognini] has been my best level in the tournament," Nadal said. "It's normal, too, because I was able to practice for two days in a row. That makes an important difference. 

"But at the same time, it's important to find positive feelings now. My physical condition needs to keep improving. But I think this match helps, too.

"I was not able to practice the proper way for the last 19 days, but yesterday [Sunday] I started again to increase the amount of work on the practice, and today has been a positive victory with some long points, so that helps for the next match."