This is Proteas' second loss to Australia in the 50-over World Cup semis. The first-ever semis meet between these two sides was tied and Aussies went to finals on the basis of better net-run rate in 1999. After that, Australia won once again in the semis against Proteas in 2007 and now they have won again.
South Africa have lived up to the "chokers" tag again, once again denied a maiden spot in finals. They also reached semifinals in 1992, 1999, 2003, 2007 and 2015, but could not win there as well.
In the chase of 213 runs, Australia was off to a fine start. Openers Travis Head and David Warner played some big shots, putting pressure on pacers Marco Jansen and Kagiso Rabada.
Head and Warner smashed Jansen for 15 runs in the fifth over. In the very next over, Rabada was smashed for three sixes by Warner and Head, 21 runs in total.
Australia reached the 50-run mark in 5.3 overs.
Aiden Markram's part-time spin did the trick for Proteas as he clean bowled Warner for 29 off 18 balls, with one fours and four sixes. Australia was 60/1 in 6.1 overs.
Mitchell Marsh was the next Proteas victim as he was removed by Rabada, thanks to a brilliant catch by Rassie van der Dussen at covers for just one. Australia was 61/2 in 7.4 overs.
Australia was 100-run up in 13.2 overs.
Head reached his half-century in just 40 balls, with eight fours and two sixes.
Spin struck once again for Proteas, removing Head for 62 in 48 balls, with nine fours and two sixes. Australia was 106/3 in 14.1 overs.
Marnus Labuschagne was next up on the crease. But South Africa continued their spin choke, removing Labuschagne for 18 and Glenn Maxwell for just one. SA was 137/5 in 23.4 overs.
Australia reached the 150-run mark in 27 overs.
Steve Smith and Jos Inglis started building a partnership and slowly took Australia near the target. But Gerald Coetzee reignited hopes of Proteas by getting the big wicket of Smith for 30 off 62 balls. The batter skied one high in the air but was caught by de Kock. Australia was 174/6 in 33.3 overs.
Mitchell Starc and Inglis rotated the strike and took Aussies into the 190s. Coetzee got his second wicket, delivering another jolt to Aussies by removing Inglis for 28 off 49 balls, with three fours. Australia was 193/7 in 39.5 overs.
Australia reached the 200-run mark in 42 overs.
Australia needed seven in last five overs. Australia finished the game with a four by Cummins. Australia finished at 215/7 in 47.2 overs, with Cummins (14*) and Starc (16*) unbeaten.
Shamsi (2/42) and Coetzee (2/47) were the pick of the bowlers for SA. Markram, Rabada and Maharaj got a wicket each.
Earlier, David Miller's century powered South Africa to 212/10 against Australia in the second semi-final match of the ongoing ODI World Cup at the Eden Gardens in Kolkata on Thursday.
Miller scored 101 runs from 116 balls and was the only standout batter for the Proteas. On the other hand, the Aussie bowling attack dominated the first inning after taking early wickets in the second semi-final match.
After winning the toss, South Africa decided to bat first in Kolkata. Quinton de Kock and Temba Bavuma opened for the Proteas but could not make a mark in the game.
Aussie pacer Mitchell Starc made the first breakthrough in the game after he dismissed Proteas skipper Bavuma for a four-ball duck in the sixth ball of the first inning (SA 1-1).
Josh Hazlewood picked up his first wicket of the match he removed De Kock in the 5.4 overs for three runs (SA 8-2).
Australia totally dominated the first 10 overs of the game after they picked up two wickets in the first powerplay. On the other hand, South Africa scored 18 runs.
Starc picked up another big wicket after he dismissed Aiden Markram in the 10.5 overs for 10 runs from 20 balls (SA 22-3).
Rassie van der Dussen had to leave the crease after Hazlewood picked up his wicket in the 11.5 overs for just six runs (SA 24-4).
After the end of the 14th over in the first inning, the game was stopped for a while as rain played a spoilsport in Kolkata.
The Proteas reached the 100-run mark in the 27.6 overs.
Aussie right-arm off-break bowler Travis Head dismissed Heinrich Klaasen for 47 runs from 48 balls in the 30.4 overs (SA 119-5).
Just after dismissing Klaasen, Head picked up Marco Jansen's wicket in the 30.5 overs for a duck. However, the Aussie bowler could not complete his hat trick in his next ball (SA 119-6).
In the second powerplay, South Africa scored 138 runs. While the Aussie bowling attack bagged four wickets.
The Aussie skipper Pat Cummins bagged his first wicket of the game after he dismissed Gerald Coetzee in the 43.3 overs for 19 runs (SA 172-7).
Starc removed Keshav Maharaj in the 46.2 overs for three runs (SA 191-8).
In the 47.1 overs, David Miller slammed his century from 115 after he smashed a six. Miller's stellar knock came at a time when the Proteas were struggling in the game.
South Africa crossed the 200-run mark in 47.1 overs.
Cummins picked up a big wicket in the game after he dismissed Miller for 101 runs in the 47.2 overs (SA 203-9).
The Aussie skipper ended South Africa's inning in the 49.4 overs after he dismissed Kagiso Rabada for 10 runs (SA 212-10). Tabraiz Shamsi stayed unbeaten till the end.
On the other hand, Mitchell Starc led the Aussie bowling attack after he bagged three wickets in his 10-over spell and gifted only 34 runs.
Pat Cummins also picked up three wickets in the game. While Josh Hazlewood and Travis Head bagged two wickets in their respective spells.
Brief score: South Africa: David Miller 101(116), Heinrich Klaasen 47(48), Gerald Coetzee 19(39) vs Australia: Mitchell Starc 3/34, Josh Hazlewood 2/12, Pat Cummins 3/51.