Published: 2018-01-08 21:47:50 BdST
England captain Joe Root raced from his hospital bed, where he had been treated overnight for gastroenteritis, to try to rescue a face-saving draw but when he failed to reappear after lunch the die was cast for the tourists.
Australia's bowling attack - the potency of which has been one of the main points of difference between the two sides - mopped up the last four batsmen at the cost of just 36 runs after the break at Sydney Cricket Ground.
"The cricket we have played has been outstanding," said Australia captain Steve Smith, whose batting was another major factor in the triumph.
"This team has been magnificent in this series, the cricket we've played has been great so I think the more we play together the more we are going to get better as a group. We have just got to keep getting better and improving as a team."
Cummins was named man of the match for his total haul of 8-119 while Josh Hazlewood performed the coup de grace when he had James Anderson caught behind for two.
Nathan Lyon (3-54) had taken the only wicket of the opening session as he continued his dominance of Moeen Ali (13), who has fallen seven times in nine innings to the off spinner in the series.
Australia's batsmen also played a full part in the return of the coveted urn, with Mitchell Marsh, his brother Shaun and Usman Khawaja all getting into three figures as the hosts made 649 declared in their reply to England's first innings 346.
"Everyone's had an impact and that's what has been so special about it, it hasn't just been one or two guys stepping up and doing the job," Smith added.
Despite Smith's determination to share the credit, he was the inevitable selection as player of the series after scoring 687 runs at an average of 137.4, backing up his status as the world's top batsman.
"I am really proud of the way that I have played in the series and led from the front," he said.
"My mind is probably in as good a space as it has been with my batting."
England managed only three centuries to Australia's nine over the series, with Smith alone matching their tally.
"We've not played well enough and they've deserved to win. They're well within their rights to be over the moon with that win," he said.
"But I do think it’s been closer than 4-0. We’ve been on top in some games, if not all the games at some stage. They’ve just played those pressurised moments better than us."
The tourists will also take pride from refusing to buckle despite being outclassed in four of the five tests and Root's determination to bat on Monday typified their fighting spirit.
The 27-year-old was 42 not out with England 93 for four at close of play on day four but he experienced diarrhoea and vomiting overnight and was taken to hospital for treatment.
Root received an ovation when he came out to resume his innings and had soon secured his 37th test half century with three runs to fine leg.
He suffered a recurrence of the symptoms during the lunch break, though, and Tom Curran came out to bat in his place, leaving Root retired hurt for 58 and sleeping in the dressing room when Australia paraded the tiny trophy.
"We've known for a few weeks they're going to lift the urn, but seeing them do it in person is tough to watch," said Anderson.
"All the guys in the dressing room are hurting. That feeling that you get should make you determined to win the Ashes back in 2019."