Australian Open: Rafa Nadal says fourth round win was his best since coming back from injury

The Spaniard boasted an impressive 7-0 record against Khachanov ahead of their clash, with the 20-time Grand Slam winner having only dropped one set against him in those meetings.

Nadal did drop another to him on Friday morning, but ended up on the winning side as he claimed a 6-3 6-2 3-6 6-1 victory.

Having won both of his first two matches in straight sets, Nadal looked to make it three in a row, as the 35-year-old raced to a 2-0 lead.

But, Khachanov gathered his composure and looked convincing as he took the third.

Not one to be flustered, Nadal immediately shut down any signs of a comeback in the fourth set, breaking Khachanov early on before celebrating passionately.

After sealing the win, the tournament's sixth seed said, "It's a very special week for me coming back from where I'm coming. Every single time I'm able to play here is a very special thing."

Nadal came into the Australian Open off the back of a lengthy absence, force on him by an ongoing foot injury last season.

However, the former world No.1 is happy with his progress since returning from injury, and pointed out Friday's performance as his best yet.

"Tonight I played against a great player and a good friend on tour. It has been without a doubt my best match since I came back. Nights like today mean everything. It's a lot of energy in my pocket to keep fighting every single day."