Century for Steve Smith. It's a phrase which has become part of the soundtrack of this season, one which MS Dhoni must be sick of hearing though it will be ringing in his ears on the long flight home to India.

Dhoni's squad arrived in Australia four-and-a-half months ago with the Border-Gavaskar Trophy and their cherished World Cup in their baggage but they will go home empty handed. Smith's heroics are a major reason why.

And it was only fitting that Smith should haunt them one last time, in arguably the biggest game the two nations have played in this long summer.

When Smith draws up his Christmas wish list every year, playing India must be at the top, such is the hold he has over them. His white-hot form against the subcontinental giants continued on Thursday when he crunched his maiden World Cup ton.

Smith is not captain yet but, with his imperious 105 off 93 balls, he provided more compelling evidence as to why he has been anointed as Australia's next long-term leader.

His fifth international century in seven matches against India this summer took his tally to 921 runs at the princely average of 115. And it was arguably more important than any of the big scores he made during the Test series.

Duncan Fletcher should not be short of footage on Smith's game, so often has the batsman held court in the past few months, but the Indians still have no clue how to get him out.

Line and length did not work during the Tests, primarily because their bowlers were unable to sustain it for long enough, and by the end of the series they had their fingers crossed hoping they could strangle him down the leg side.

This time they tweaked their plan slightly, preying - or was it praying - on his habit of shuffling across the crease in a bid to trap him lbw. It proved as unsuccessful as anything else they have tried in the past few months.

Australia's fortunes with the bat rode with Smith. They were scratchy while he was padded up in the dressing room, in command when he was at the crease and again uncertain when he was back in the shed.

It now seems hard to believe Smith began the summer out of Australia's one-day team. Had Michael Clarke's hamstrings not given way in Perth in November, he may not have had the chance to make his priceless contribution.

Smith was in total control, displaying the calmness and assuredness synonymous with Clarke at his pomp.

The difference between the two, however, is Smith has extra gears and the whiz-bang shots in his kit bag shared by many of his contemporaries in the Twenty20 era to go with the nuts and bolts defence which makes him a world-class Test batsman.

"Getting into good form and scoring runs is a fantastic feeling but still to go to training the next day to work on your game and try to become better it's one of the hardest things to do in this game," Clarke said of Smith.

"But that's what makes you a great player and that's what I'm been really proud with Smithy for. He's still training really hard, still getting there early, still doing the work, even though he's batting so well. I can't say I'm surprised that he's getting the results that he's getting. He's earned it."

For long periods, it was as if India had given up on getting Smith out, giving him easy singles to get him off strike and allow them to have a crack at Aaron Finch - who seldom looked comfortable but showed plenty of grit to make 81.

Umesh Yadav tried a series of bumpers but Smith made good his promise of punishing anything short, unleashing a stream of boundaries. Appropriately, he posted his century off a meek half-tracker from Mohammed Shami.

"I got a few freebies early on, a couple of short ones that weren't quite short enough and I got a few boundaries away, that really got my innings started," Smith said.

That he met his end to the short ball did not matter. Australia already had one foot in the final.