Canadian title hopeful Felix Auger-Aliassime has surged back from two sets down against Alex Molcan to book his spot in the third round of the Australian Open.
The unheralded Slovakian made all of the early running under the closed roof at Rod Laver Arena on Wednesday.
But a costly double fault in the eighth game of the third set gifted the sixth-seeded Auger-Aliassime a crucial break and he never looked back
The revitalised Canadian peeled off 15 of the last 19 games against an increasingly-frustrated Molcan to win 3-6 3-6 6-3 6-2 6-2 in a tick over three hours.
"When I won the third set I got a lot more self-belief," said Auger-Aliassime.
"I'm very pleased to get it done.
"It was a tough day for me."
Auger-Aliassime will next play either No.28 seed Francisco Cerundolo from Argentina or Frenchman Corentin Moutet in the round of 32.
The 22-year-old enjoyed a breakout year in 2022, winning his first four Tour-level titles.
He also reached the quarter-finals at Melbourne Park last year before falling to eventual runner-up Daniil Medvedev.
Italian No.16 seed Jannik Sinner enjoyed a much more comfortable path into the third round, needing just one hour, 44 minutes to see off the challenge of Argentina's Tomas Martin Etcheverry 6-3 6-2 6-2.
The 15th-seeded Sinner has made a flying start to the opening grand slam of the year, dropping just 13 games in total in his two wins over Britain's Kyle Edmund and Etcheverry.
He did not face a single break point against the Argentine world No.79.
"I'm very happy to be in the next round," said the 21-year-old Sinner, who is co-coached by Australian Darren Cahill.
"I'm very happy to play again on this court with the roof, especially as it's raining outside.
"I served well and also returned well today."
Sinner will play either South African Lloyd Harris or Marton Fucsovics from Hungary in the round of 32.
Persistent rain in Melbourne continued to prevent any play on the outside courts.
Other leading men in action on Wednesday include No.3 Stefanos Tsitsipas and seventh-seeded Medvedev.
Tsitsipas will play Australian wildcard Rinky Hijikata, who came from two sets down to claim his maiden grand slam win on Monday against German Yannick Hanfmann.
Medvedev - the beaten finalist in each of the past two years at Melbourne Park - also takes on a local hope in the second round in John Millman.
