Australian Open favourite Rafael Nadal reflected on a "very special week" after he progressed to the fourth round in Melbourne for the 15th time in his career.

Nadal cruised into a two-set lead against Karen Khachanov on Friday, though the Spaniard had to overcome a third-set fightback to win 6-3 6-2 3-6 6-1.

The 35-year-old - who triumphed at the Melbourne Summer Set earlier in January - has won all six of the matches he has played so far in 2022.

Nadal has endured a difficult time with injuries in recent seasons but, with Novak Djokovic out of the picture after his deportation from Australia this week, he has a record 21st grand slam triumph firmly in his sights.

"It is a very special week for me, coming back," said Nadal, who was out of action from August until December, when he played in an exhibition event in Dubai.

"Every single time I am able to play here is very special. I played against a great player and a good friend on Tour. It was my best match since I have come back without a doubt.

"I have gone through some very tough times over the past year, but nights like tonight mean everything.

"I keep fighting and going every day. I put a lot of effort in to be back with where I am today, so I am happy."

Nadal has won all eight matches against Russian Khachanov, and he will face Adrian Mannarino, whose four-set win over Aslan Karatsev concluded late into the Melbourne night.

He may only have won the Australian Open on one occasion, in 2009, but only Roger Federer (18) has reached the fourth round in Melbourne on more occasions than Nadal.