Australia need a 14-wicket final day to defy Sydney’s poor weather and claim a 3-0 series sweep of South Africa after Pat Cummins breathed life back into the rain-soaked Test on day four.

South Africa went to stumps in their first innings at 6-149 and needing 127 more runs to avoid the follow-on, after Australia declared at 4-475 with Usman Khawaja unbeaten on 195.

It came after the first half of the day was washed away by rain and leaky covers, adding to the loss of all day three and another 57 overs across the opening two days.

Australia must win the match to wrap up a spot in June’s World Test Championship final, taking qualification out of the equation before next month’s four-Test tour of India.

The first task will be to dismiss South Africa for 275 or less in their first innings, allowing the hosts to enforce the follow-on and push for the win.

Australia’s bowlers have given them every chance of doing so.

Cummins claimed 3-29 on Saturday, as he bowled with fury in fading light late after he earlier had Heinrich Klaasen caught behind before tea.

Cummins’ masterclass

The quick set up Khaya Zondo when he bounced him from around the wicket late in the day, before he followed up with a yorker and trapped him lbw for 39.

The in-form Kyle Verreynne also fell to Australia’s captain on 19, edging Cummins to slip after he and Zondo had led a brief fightback for the Proteas with free-flowing strokeplay.

But with Verreynne’s exit, the tail is exposed to start the final day.

Hazlewood also bagged two wickets in Australia’s charge, as he extended South Africa captain Dean Elgar’s woes with a well-placed bouncer that caught the opener’s glove on 15.

Temba Bavuma was Hazlewood’s other victim, caught behind when he hung his bat outside off stump to a seaming delivery and offered his outside edge.

Nathan Lyon also out-smarted Sarel Erwee to claim the opener’s wicket earlier in the day, with a ball that went straight on and brushed the leaving left-hander’s off stump.

Australia’s one moment of disappointment came when third umpire Richard Kettleborough deemed the ball had brushed the ground as Steve Smith claimed a brilliant catch at slip with Elgar on six.

The incident came after a similar appeal was turned down in Australia’s innings on day one when Simon Harmer believed he caught Marnus Labuschagne on his way to 79.

-AAP