A respected Melbourne surgeon's killer will spend at least a decade behind bars after becoming the first person sentenced under Victoria's "coward-punch" laws.
Patrick Pritzwald-Stegmann, 41, suffered fatal head injuries when struck by Joseph Esmaili at Box Hill Hospital in May 2017.
The killer, now 24, was found guilty of manslaughter last year and was on Wednesday ordered to spend up to 10 years and six months in prison.
He's the first person to receive a mandatory minimum decade-long prison term under Victoria's coward-punch laws, meaning he must serve at least 10 years before being eligible for release on parole.
Mr Pritzwald-Stegmann paused on his way home to ask a group - including Esmaili - to stop smoking near the hospital entrance.
A loud and aggressive row broke out, captured on CCTV.
"Unfortunately neither of you was prepared to simply walk away from the argument," Justice Elizabeth Hollingworth told Esmaili.
"Suddenly, and without warning, you pulled your right hand out from behind your back, and punched him with a clenched first to the head."
The force of the punch knocked Mr Pritzwald-Stegmann unconscious. He fell straight to the floor, hitting his head and sustaining catastrophic brain injuries.
Esmaili ran from the hospital as medical teams raced to save the doctor.
Family switched off life support a month later.
Widow Christine Baumberg said Mr Pritzwald-Stegmann was first and foremost a loving husband and father. Their twin daughters were five when he died.
He was also a dedicated heart and lung surgeon who spent his days dealing with cancers and other harmful effects of smoking, she said, calling for stricter enforcement of hospital smoking bans.
The sentence reflected Esmaili's "total lack of responsibility and remorse" following a trial in which he'd blamed everyone but himself for her husband's death, she said.
Justice Hollingworth also took aim at Esmaili's continued self-defence argument, though noted he had expressed some remorse.
"You still have some way to go before you genuinely accept responsibility for your actions that day," she said.
Victoria's one-punch laws were introduced in 2014.
Earlier bids for mandatory minimum sentences for Richard Vincec, who killed Jaiden Walker in 2017, and Andrew Lee, who fatally punched Patrick Cronin in 2016, were withdrawn by prosecutors before sentencing.
Before the decade-long minimum can be sought they must prove a single strike to the head alone caused death, that the victim was not expecting the punch and the attacker knew it was unexpected.
Caterina Politi, whose 22-year-old son David Cassai was killed in a one-punch attack at Rye in 2012, cried tears of grief and relief outside court at the fact the law had been used, but wants it applied to all deaths by assault.
"If there was no CCTV they could not prove that the doctor wasn't expecting to be punched. He's not here to tell us," she said.
"To have to prove these points is excruciating and you don't always have the luxury of CCTV."