SYDNEY: Steve Smith's golden summer just keeps on getting better.

Australia's new run-scoring machine just can't seem to do any wrong and now he's off to the World Cup final.

Smith has been piling on the runs and breaking records all summer long. And on Thursday, in one of the biggest matches of his blossoming career, he did it again, scoring a match-winning century in the World Cup semi-final against India.

Smith's 105 was a composed and perfectly-constructed innings. He came to the crease early after Australia lost David Warner in the fourth over and quickly settled the host nation's nerves.

The 25-year-old reached his fourth straight half century at the World Cup in 53 balls then his hundred off 89 balls, which he brought up with a six and a four off successive balls.

He departed soon after but the job had been done. Australia went on to post a massive total of 328-7 and India could only manage 233 in reply.

“We thought 330 was around par. We knew we had to bowl and field well,” Smith said after being named man of the match.

“The boys did a terrific job tonight. Bring on Melbourne.”

Australia will play New Zealand in the final in Melbourne on Sunday.

For Smith, his century continued his amazing run of form with the bat this summer.

In the four-test series against India, which started in November, he scored a century in every match.

In the months leading up to the World Cup, he also scored one-day international centuries against South Africa and England before notching his first World Cup hundred on Thursday.

And for good measure, he also pulled off a brilliant piece of fielding, running out Ravindra Jadeja with a direct hit.

Smith's extraordinary run has coincided with his surprise promotion to the Australian captaincy.

When regular skipper Michael Clarke hobbled out of the first test against India with a hamstring injury, Smith was given the nod as Australia's 45th test skipper and hasn't looked back.

“It's nice to contribute to a few wins. It was a pretty big stage tonight, semi-final of a World Cup,” Smith said.

“I'm just happy we got over the line in the end.

“I'm just looking forward to Melbourne. It got to be a hell of a day.”

Smith was always destined for greatness but even his most loyal supporters have been astounded by his rapid rise.

He was picked for Australia's test team in mid 2010, aged 21, starting his career as a promising leg-spin bowler and middle-order batsman.

But he was dropped from the test team in early 2011 and took almost two years to fight his way back in, but returning as a top-order batsman with an insatiable appetite for scoring runs.

Now, Smith is dreaming of one more hundred, in the World Cup final.

“I hope so, hopefully another big hundred would be nice,” he said.

“It's going to be an amazing moment, to play a World Cup final against New Zealand at the MCG. Can't wait to get down there.”