Australia face a battle to qualify for the Cricket World Cup semi-finals after losing by 134 runs to South Africa in Lucknow.

The Baggy Greens went into Thursday's contest on the back of a six-wicket defeat to India at the weekend, putting them under pressure to respond against a rival for a last-four spot.

Instead, Australia were never competitive against the Proteas, with Quinton de Kock hitting 109 before the South African bowling attack proved too strong with the ball.

Despite losing the toss, South Africa dominated the opening 20 overs with the bat, De Kock and Temba Bavuma putting on 108 for the first wicket.

Partnerships of 50, 39 and 67 followed with Aiden Markram making 56 off 44 balls, but it was De Kock's 109 from 106 deliveries that stood out, the opener contributing eight fours and five maximums.

Although South Africa's run-rate slowed down towards the end of the innings, they reached 311-7 from their 50 overs, with Glenn Maxwell's 2-34 the only bowling figures of any note for Australia.

In response, Australia lost three wickets inside the opening 9.5 overs as Mitchell Marsh (7), David Warner (13) and Steven Smith (19) all failed to post a significant contribution.

Australia soon dropped to 65-5, already leaving them in a position where avoiding a heavy hit on their net run-rate was becoming a priority, but Marnus Labuschagne dug deep with a knock of 46 to salvage some pride.

Mitchell Starc (27) and Pat Cummins (22) kept things ticking over down the order, but Australia were bowled out for 177 with 55 balls of their allotted 50 overs left.

Four of South Africa's bowling attack took at least two wickets apiece, Kagiso Rabada the star with 3-38, but this was a team effort, one which leaves Australia with a net run-rate of -1.846 ahead of what feels like a must-win showdown against Sri Lanka. body check tags ::