Quinton de Kock cracked his second successive century at the World Cup on Thursday as South Africa demolished five-time champions Australia by 134-runs.
After the Proteas had made 311-7 – with de Kock top-scoring with 109 off 106 balls – Australia lost six wickets with just 70 on the board and then focused trying to limit the damage to their net run-rate.
They were eventually dismissed for 177 with 55 balls to spare as fast-bowler Kagiso Rabada took 3-33, while Marco Jansen, Keshav Maharaj and Tabraiz Shamsi all took two wickets each.
Marnus Labuschagne's 74-ball 46 was the top score for Pat Cummins' side who fell to their biggest World Cup defeat.
There was controversy over Marcus Stoinis's wicket after South Africa called for a review, which left Australia 70-6 in their chase.
Third umpire Richard Kettleborough deemed the right-hander had gloved Kagiso Rabada down the leg side, but replays suggested Stoinis' hand was off the bat when the ball grazed that glove.
Kettleborough's explanation was both Stoinis' gloves were touching, but that did not appear to be the case on the pictures shown.
But that decision cannot not paint over what was a woeful batting display from Australia.
“Not much needs to be said tonight, everyone's hurting,” said captain Cummins.
“We were well off the mark. If we want to be challenging for this tournament you've got to adapt to all conditions.”
For South Africa, it was a second win in two games after their record-breaking victory over Sri Lanka in their opener.
Australia, meanwhile, have lost both of their matches after hosts India ran out winners by six wickets on Sunday.
The left-handed de Kock continued his sublime batting form in his last major international tournament in a 108-run opening stand with Bavuma.
The South Africa skipper was dropped twice before he aimed a big shot against Glenn Maxwell and holed out to David Warner.
But de Kock was hardly troubled by the Australia pace or leg-spin of Adam Zampa as he scored his 19th ODI century with eight fours and five sixes at the venue where he plays for the Indian Premier League team Lucknow Super Giants.
De Kock shared another half-century stand with Rassie van der Dussen (26) before he was bowled by Maxwell in the 35th over while going for a reverse sweep.
“I’ve seen from the Lucknow team it gets harder at night and it did prove that,” de Kock said. “We are pretty pleased with ourselves, but only two games in, anything can happen and quickly. We won’t get too high, just take it game by game.”
Australia's next game is against Sri Lanka at Lucknow on Monday while South Africa face the Netherlands on Tuesday in Dharamsala.