The 23-year-old came through a tense battle between the world's top two players 6-3, 7-6 (7/4), 6-3 on Rod Laver Arena, raising his arms in the air and looking to the sky in celebration.
The victory earned the Italian world number one his third Grand Slam crown.
The former world number one responded on Saturday, posting a photo of an MRI taken of his left hamstring on the social media platform X with the caption: "Thought I'd leave this here for all the sports injury 'experts' out there."
It is Keys's first major title, having reached a second Grand Slam final eight years after her first in New York. She lost on that occasion to Sloane Stephens
Sinner's coach Darren Cahill said it was no surprise for him to see his young charge back in the final, but they were wary of the threat posed by Zverev's overarching desire to finally win a Slam.
The American battled injury and self-doubts last year and curtailed her season early, in October, to get married.
Swiatek said she made far too many mistakes against Keys on Rod Laver Arena and hoped to draw lessons from it.
The 19th seed powered through a thrilling semi-final on a final-set tiebreak against the world number two 5-7, 6-1, 7-6 (10/8) after Sabalenka had earlier swept aside Paula Badosa in straight sets.
The Italian top seed faces Ben Shelton on Friday, just two matches away from a first successful Grand Slam title defence after winning his maiden major crown in Melbourne last year.
Novak Djokovic and Rafael Nadal kickstart their 2023 campaigns this week in Adelaide and Sydney respectively, with the superstar veterans and great rivals eyeing up yet more Australian Open glory.
Novak Djokovic will be able to bid for a record-extending 10th men's singles title at next year's Australian Open after being granted a visa to travel to the tournament.
Former world number one Novak Djokovic will be granted a visa to play in the 2023 Australian Open, local media reports said Tuesday, despite his deportation from the country ahead of this year's tournament in January.
Novak Djokovic is eager to play at the Australian Open but it's up to him to "work out the situation" with the government, tournament chief Craig Tiley said Wednesday, while confirming Russians and Belarusians can compete as neutrals.
Battle weary Simona Halep says her time will come after failing for the third time to win a Grand Slam final, admitting her body simply gave up after a draining Australian Open.
Maria Sharapova returns to tennis this week following her 15-month ban having tested positive for meldonium at the 2016 Australian Open.
A new multi-purpose 5,000-seater stadium is to be built at Melbourne Park as part of efforts aimed at keeping the Australian Open grand slam tennis tournament at its current site, Victoria state treasurer Tim Pallas said on Sunday.
Roger Federer showed few signs of rust after a month off following his Australian Open heroics in sending Benoit Paire packing at the Dubai Tennis Championships on Monday.
Novak Djokovic and Nick Kyrgios hope the Davis Cup heals the wounds of their painful Australian Open exits this weekend when they will be the only two men in the top 15 taking part.
Maria Sharapova said Wednesday she refused to feel sorry for herself during her doping ban, occupying her time by studying at Harvard, writing a book and even learning how to box.
