Rafael Nadal booked his spot in the fourth round of the Australian Open after seeing off an inspired Karen Khachanov in four sets on Friday night.

The 20-time Grand Slam champion marched to a 6-3 6-2 3-6 6-1 victory over the Russian at the Rod Laver Arena, storming into an early 3-0 lead in the first set.

Nadal immediately broke Khachanov's serve in the second set before his opponent clawed it back to 5-2 following a flurry of aces, but Nadal served for the set as Khachanov's backhand return flew into the net.

However, the Russian earned his first break of the match in game four of the third set before recovering from 40-0 down to hold at 4-1, ultimately forcing a fourth set with a love hold.

Nadal proceeded to let out a huge cry after breaking Khachanov's serve in game two of the fourth set and was in control from thereon in, advancing to the last-16 after Khachanov failed to return a mammoth serve.

"It is a very special week for me, every time I am able to play here is a very special thing. I played against a great player and a good friend on tour, it has been my best match since I came back," Nadal said during his on-court interview, as quoted by BBC Sport.

"I have been going through some very tough times the last year and a half but for me nights like today mean everything, that is a lot of energy in my pocket to keep going. I am super happy, thank you very much everybody."

Nadal will now meet Adrian Mannarino for a spot in the quarter-finals. body check tags ::