Roger Federer came perilously close to catching the upset bug at the Australian Open but recovered to beat John Millman in five dramatic sets and reach the fourth round.
The third seed trailed 8-4 in the deciding tie-break but won six points in a row, clinching a 4-6 7-6 (2) 6-4 4-6 7-6 (8) victory with a forehand winner.
Even Federer struggled to believe he had found a way out, saying: "It was tough. Thank God it's a super tie-breaker otherwise I would have lost this one.
"I think John played a great match. It came down to the wire, a bit of luck maybe. I had to stay so focused, take the right decisions. He kept on coming up with the goods.
"I thought, 'OK, I didn't play too bad'. I was getting ready to explain myself in the press conference. What a match. John deserved over half of this one."
Having seen Serena Williams and Naomi Osaka lose on Rod Laver Arena before him, it would have been understandable had Federer felt a few extra nerves, particularly given Millman had been the opponent for one of the most uncomfortable nights of his life.
That came a year and a half ago at the US Open, when the likeable Queenslander knocked out Federer in extreme heat and humidity.
Conditions were very different in Melbourne but there was plenty more discomfort for the 38-year-old, who struggled to find his timing and was a break down in the deciding set.
This was the biggest match so far to be decided by the first-to-10-point tie-break introduced last year, and it was an extraordinary denouement.
Federer made 82 unforced errors, 48 of them off the forehand, but this was a night where his competitive resilience was the biggest weapon in his armoury as he kept alive his hopes of winning a 21st grand slam title.
If he is to have a chance of doing that, he will need to play a lot better, starting against Hungary's Marton Fucsovics in round four.
Federer came unstuck in the fourth round 12 months ago against Stefanos Tsitsipas, but the Greek was the hunted this year as he tumbled out 7-5 6-4 7-6 (2) to Milos Raonic.
Big-serving Canadian Raonic has endured wretched luck with injuries over the last few years but was in supreme form.
Tsitsipas had never faced the Raonic serve before, and he said: "You're just there, getting punched in the face with one shot. I felt a bit stupid returning his serves. I felt like I was slow."
Raonic will next face 2018 finalist Marin Cilic, whose latest victory came in five sets over Roberto Bautista Agut.
Defending champion Novak Djokovic defeated Yoshihito Nishioka 6-3 6-2 6-2.