Rafael Nadal has declared himself pleased following an improved performance that saw him past Kevin Anderson at the Australian Open.

The Spaniard breezed into the quarter-finals of the Melbourne Grand Slam with a comfortable straight-sets win over the South African.

Nadal is now excited about his last-eight matchup against Tomas Berdych.

"[Berdych] is playing great. Will be a very tough opponent, no?" he told reporters after his victory.

"But for me, quarter-finals is a great result, talking seriously. Arriving here, losing in the first round of Qatar, not playing matches for the last seven months, to have the chance to be in quarter-finals again here is a very positive thing for me.

"I try to play better and better every day. If that happens, I hope to keep having chances for the next match. But today is a day to be happy the way that I improved my level of everything... all the things I have to do on court."

Nadal saved six set points in the first set of his last-16 win.