World No. 1 and Australian Open favorite Rafael Nadal continued to tick like a metronome, overpowering 15th seed Croatian Marin Cilic in Melbourne on Monday.

Spaniard Nadal played well in the fourth round by winning Cilic 6-2, 6-4, 6-3 in two hours 31 minutes, and reached to quarter finals in Australian Open for the 5th straight year.

His pressure on the 15th seed's serve was constant and stifling, breaking Cilic in the opening game and finishing with another break, the Croatian double-faulting to hand the Spaniard victory.

Nadal only offered two break points on his own service game, neither of which Cilic could convert.

"Before the match I was a little bit nervous because he is very dangerous and I tried to play with high intensity," he told reporters in Melbourne after the game.

"I am very happy because I played my best match of the year at the Australian Open."

Nadal has been suffering from a virus in recent weeks but he claimed he was over the worst

"I am not sweating that much tonight, in previous days I was sweating like crazy and I was feeling very tired," he said.

"Today was the first time that I felt perfect physically."

The 24 years-old Nadal won the French Open, Wimbledon and the U.S. Open last year and is trying to become the first man to hold all four major titles simultaneously since Australia's Rod Laver in 1969.

He sets a final eight encounter with 7th seed Spanish David Ferrer, who earlier on Monday defeated Milos Raonic 6-4, 2-6, 3-6, 4-6.

This will be the first all-Spanish quarter final at Melbourne Park since 1997 when Carlos Moya defeated Felix Mantilla.