Nick Kyrgios threw a barrage of aces, tweeners and underarm serves at Dominic Thiem in front of a raucous crowd on John Cain Arena before the 11.30pm curfew hit Melbourne, but last year's finalist soaked it all up before rallying from two sets down to break Australian hearts.
Thiem, last year's runner-up and the current US Open champion, appeared to be heading for an early exit after falling two sets down to home favourite Kyrgios but he rallied brilliantly to make it through to the fourth round, winning 4-6 4-6 6-3 6-4 6-4.
"That first match against Nick here on his favourite court with an amazing crowd, there are easier things to do," said Thiem. "That's one of the tougher challenges we have in our sport, you never know what's coming.
"I was fighting myself in the match but after the US Open nothing's impossible. That match showed me giving up is never an option.
"I always prefer playing in front of a crowd, even if they are not for me. They are obviously for the local hero, there's nothing wrong with that.
"I prefer that to playing in an empty stadium. Tonight was epic and a good last match before lockdown."
Melbourne officials announced that spectators would have to leave the site by 11.30pm before a five-day lockdown.
The announcement was met with boos from the crowd on the John Cain Arena, where Kyrgios was treating the fans to some scintillating shot-making in a breathtaking match.
He looked to be heading for a famous win when Thiem produced a comeback for the ages to send a baying crowd home in disappointment with just under an hour to spare before the curfew hit.
The Austrian was shellshocked for the first two sets, barely able to lay a glove on Kyrgios, who channelled the crowd's energy to produce some electrifying tennis.
But Thiem transformed from timid to terrific as his serve revived, and he lived to set up a battle with Grigor Dimitrov for a quarter-final spot after sealing the match with a majestic backhand down the line.
Bulgarian Dimitrov, seeded 18th, made it through after Spain's Pablo Carreno Busta was forced to retire with illness after losing the opening seven games.
Kyrgios said: "I took 13 months away from the game and to produce that level and go toe to toe with one of the best players in the world, I'm pretty proud. I left it all out there.
"He's a hell of a player. He's so disciplined. He's so composed. His level doesn't drop. It is what it is."
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Unknown Russian Aslan Karatsev caused a major shock in the men's draw when he destroyed eighth seed Diego Schwartzman in straight sets.
The 27-year-old qualifier, ranked 114 in the world and playing at his first Grand Slam, stunned Argentinian ace Schwartzman 6-3 6-3 6-3 on John Cain Arena.
He showed nerves of steel as he closed out the match of his life with an ace down the middle.
Karatsev, who suffered a serious knee injury in training in 2017 which kept him out for six months, led the ATP in Challenger wins in 2020, and he's now 6-0 in 2021 after dropping just one set in qualifying.
He was a member of Russia's triumphant ATP Cup team last week, as a doubles player, but did not play a live match due to the form of singles stars Daniil Medvedev and Andrey Rublev.
Karatsev said on court: "I had a big injury on my knee but after two years I recovered.
"The ATP Cup was great, we have unbelievable players in Daniil and Andrey, and it gave me a lot of confidence when we won."
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Felix Auger-Aliassime won the all-Canadian battle against Denis Shapovalov on Margaret Court Arena 7-5 7-5 6-3, while veteran Milos Raonic advanced to the fourth round for the eighth time after surviving a mid-match wobble to beat Marton Fucsovics of Hungary 7-6 (7-2) 5-7 6-2 6-2.
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