Sixth seed Rafa Nadal dropped his first set at this year's Australian Open but still powered through to the fourth round with a 6-3, 6-2, 3-6, 6-1 defeat of Karen Khachanov on Friday.
The Spaniard, seeking to claim a record 21st Grand Slam title in the absence of great rivals Roger Federer and Novak Djokovic, was sensational as he took a two-set lead.
But Khachanov, seeded 28th, threw caution to the wind in the third set, stalling Nadal's charge with some ferocious hitting.
Olympic runner-up Khachanov had lost all seven previous meetings with 2009 Australian Open champion Nadal but briefly looked capable of mounting a comeback.
Nadal seized back control with a break of serve at the start of the fourth, however, and with the clock having ticked past midnight on Rod Laver Arena he finished it off in a hurry.
Nadal, who has reached the last-16 in Melbourne for the 15th time in 17 appearances, will face another Russian, 18th seed Aslan Karatsev, or Frenchman Adrian Mannarino next.
"I played a great player tonight and happy that this was my best match since coming back," the 35-year-old Nadal, who missed the second half of 2021 with a foot injury, said on court.
"I've been going through some tough times in the last year but night's like tonight mean everything."
With Federer still injured and nine-time Australian Open champion Djokovic deported after a visa row, Nadal has a chance to edge ahead of that duo with whom he shares the record for most men's Grand Slam titles.
After routine wins against 66th-ranked American Marcos Giron and German qualifier Yannick Hanfmann in rounds one and two, Khachanov represented a step up in class for Nadal despite the Russian having only ever won one set off the Mallorcan.