Nick Kyrgios will renew his rivalry with Rafael Nadal in the fourth round of the Australian Open after winning a five-set thriller on a final-set tie-break against Karen Khachanov.
The Australian 23rd seed appeared in complete control when he led by two sets to love and a break but Khachanov saved a match point in both the third and fourth sets to force a decider.
Kyrgios, 24, twice held his serve to love to stay in the fifth set before he won the deciding tie-break to clinch a 6-2 7-6 (7-5) 6-7 (6-8) 6-7 (7-9) 7-6 (10-8) win after four hours and 26 minutes.
"Man, it was crazy. I don't even know what to say right now. That was insane. I've got no words for how I'm feeling right now," said Kyrgios in his on-court interview in front of a delirious Melbourne Arena.
"This is epic. I don't even know what's going on. My legs feel about 40 kilos each.
"I was losing it mentally a little bit, obviously it wasn't easy losing the third and the fourth having match points. My support team willed me over the line. I thought I was going to lose, honestly."
Earlier, top seed Nadal marched into the last 16 - for the 13th time in his career - with a dominant 6-1 6-2 6-4 win against fellow Spaniard Pablo Carreno Busta.
It will be the eighth meeting between Kyrgios and Nadal, with the Spaniard leading 4-3 after the world No 1 won in four thrilling sets in their most recent encounter at Wimbledon last year.
Australian Open 2020: Men's Draw
On facing Nadal, Kyrgios added: "He has a winning record against me. Whatever happens between us, he's an amazing player, arguably the greatest of all time.
"I'm going to do everything I can to get ready and hopefully it will be enough."
For the second successive night, a men's singles match came down to a deciding tie-break, after Roger Federer's remarkable recovery from 8-4 down to win the final six points against Australian John Millman.
Kyrgios recorded 97 winners in a typically entertaining performance which combined the sublime and the ridiculous, including an underarm serve, several tweeners and a diving backhand winner that cut his hand and resulted in a row with the umpire over a time violation.
Khachanov fought back in a gripping finale as the Russian recovered from a 3-0 deficit to open a 8-7 lead on his serve in the final-set tiebreak.
However, Kyrgios then hit a backhand winner down the line to regain parity before he fell to the court in celebration after successive backhand errors from Khachanov.