Richardson's five scripts dramatic Australian comeback
Australia 8 for 348 (Finch 107, Warner 93, Smith 51, Ishant 4-77) beat India 323 (Dhawan 126, Kohli 106, Richardson 5-68) by 25 runs
Scorecard and ball-by-ball details
In turn imperious then inept, India tripped over in sight of the finish line at Manuka Oval to gift Australia a fourth victory from as many matches. John Hastings and Kane Richardson were the architects of a staggering passage of implosion by the visitors - losing 9 for 46 after centuries from Virat Kohli and Shikhar Dhawan had taken India to a mere 72 runs shy of victory with 75 balls remaining.
Hastings and Richardson claimed a combined 5 for 17 from 27 balls to ensure the afternoon work of Aaron Finch, David Warner, Steven Smith and Glenn Maxwell was not wasted, on a Manuka surface the Australian captain had hoped would become more difficult to bat on under lights.
For a time Smith was facing Australia's first defeat of the summer and an end to their record streak of ODI wins, but he marshalled his men grandly as India self-destructed. Their loss maintained another proud record for the hosts - never have Australia failed to defend a tally of greater than 300 on home soil.
There was one unsettling factor in India's chase: Ajinkya Rahane suffered split webbing in his right hand when fielding and a spokesman said he would bat "if required". He did not come in at his usual No. 4 position; the resultant shuffling up of MS Dhoni, Gurkeerat Singh Mann and Ravindra Jadeja played some part in the hectic collapse that was to follow.
Dhawan had shrugged off an indifferent start to the series by pushing on to a determined century, but it was Kohli who once again exhibited his genius in a run chase. This was his 15th ODI hundred when batting second, and he appeared destined to take India home. When he spooned the first ball of Richardson's ultimately pivotal spell to mid off, Kohli stood motionless at the crease in disbelief.
In front of a sold-out crowd of 10,922 as Canberra pitches for an inaugural Test match next summer, Warner and Finch added 187 to set the perfect platform before Smith and Maxwell added plenty of late-innings pyrotechnics to pile up 111 from the last 10 overs of the innings.
Batting under lights for the first time in the series, Rohit and Dhawan had been faced with the unexpected sight of Nathan Lyon taking the new ball in his first ODI since late 2014. Whatever Smith had hoped to achieve by having Lyon on early, two overs that cost 23 were not in his plan. Those early runs allowed India's chase to gain momentum against the new ball, something hardly scotched when Rohit gloved Richardson down the leg side to be nicely held by Matthew Wade.
Kohli dispatched two boundaries in the space of his first four balls, and five more allowed him to shimmy to his 50 in a mere 34 deliveries. He took a particular liking to James Faulkner, who was hammered for 29 from the 16 balls he delivered to India's Test captain. Dhawan took a similarly heavy toll on Lyon, and when George Bailey's claim for a low catch off Dhawan was found to be unfounded there seemed no other conclusion than an Indian victory.
By the middle of the 38th over India needed just 72 runs from 75 balls with nine wickets standing. But in his last over of another exemplary spell, Hastings was rewarded for keeping things tight: Dhawan sliced a slower ball to backward point, then two balls later MS Dhoni touched a leg cutter behind. The next Lyon over cost only one and Richardson, replacing Hastings, had Kohli caught at mid-off by Steven Smith off the first ball. A pitch and equation that had seemed all too straightforward for set batsmen now began more difficult proportions for new ones, and Smith closed in admirably with tight fields that also sought wickets.
Twice Smith was rewarded with catches at slip, the first an excellent low snaffle to get Rahane, while Lyon's improvement across the night was shown by the fact his final three overs reaped 1 for 15 after his first seven cost 61. India's required run rate blew out, runs became scarce, and by the end the Australians were toasting a victory that had seemed unfathomable merely an hour before.
There had been less such ebbs and flows when the hosts batted. Warner did not take long to find his range on return to the team. He had a sighter - 3 off 12 - before the new white balls began pinging off his bat with regularity. Warner launched Bhuvneshwar for a trio of boundaries in the fourth over and exposed the variable lengths and lines of the visiting attack. Three more balls sent to the fence in the next over, off Umesh Yadav, and the tone of the innings had been set.
It was to be further underlined when Finch and Warner both inflicted injuries on those in the path of their pummelling, the umpire Richard Kettleborough limping off the field after a heavy blow to the leg, before Bhuvneshwar needed treatment for a finger stung by Warner's straight drive.
From this point Warner was in complete command while Finch rode happily in his slipstream, their union only broken when the Australian vice-captain took a big swing at Ishant Sharma and dragged on, for 93. Even in this dismissal a difference between Australia and India could be seen - a looming hundred made no difference to how Warner would play.
There was something a little more hesitant in the batting of Mitchell Marsh, promoted to No. 3 for seemingly no other reason than to grant him some time in the middle now that the series is decided. The responsibility appeared to weigh heavily on Marsh, who battled for timing and also to rotate the strike, even as Finch accelerated to his second century in successive ODI innings on this ground.
Finch's increasing sense of urgency resulted in a skied pull shot well held by Ishant, to bring Smith to the middle with 12.3 overs remaining. The gulf in batting touch between Marsh and Smith was swiftly illustrated as Smith took no time at all to get into stride, one pratfall when trying to sweep Jadeja the lone exception. Marsh eventually mistimed a high ball to long-on, prompting another batting order tweak as Maxwell joined Smith.
Smith skipped to his fifty from 27 balls before falling to another skier. A hustle-and-bustle last four overs reaped 47 even as regular wickets fell and the final over cost 18 before Maxwell was out to the final ball, hobbling from the middle and later being subbed off the field after he was struck on the right knee by the ball. India fancied themselves in the chase, but for many a long year they will ask themselves a simple question: "How?"
Daniel Brettig is an assistant editor at ESPNcricinfo. @danbrettig