Another contentious third umpire review has impacted the rain-interrupted third Test between Australia and South Africa at the SCG, with match official Richard Kettleborough again in the thick of things.

With Australia deciding to declare after going without play since Day 2 of the Test, captain Pat Cummins is hoping his side can keep the Proteas under 475 runs and claim 20 wickets within less than two days of action.

Wickets atop the order will be crucial for the home nation, and the Aussies were left bemused by Kettleborough's most recent decision as the TV umpire for the match.

With South Africa 0/10 in the fourth over of their first innings, returning Australian paceman Josh Hazelwood managed to collect the edge of Proteas captain Dean Elgar, with the ball drifting to the slips cordon.

Diving to his right, Steve Smith plucked the ball with one hand and celebrated the assumed wicket.

With the on-field umpires requiring Kettleborough's assistance to assess the dismissal, the wicket was reviewed by the third umpire.

After minutes of analysing the catch, Kettleborough decided the ball made enough contact with the ground whilst in Smith's grasp to not be deemed a catch.

Much to the frustration of the Australians, and the crowd, Elgar remained at the crease as South Africa look to defend what looms as an unwinnable match for the travelling side.

"I am gobsmacked," former Australian opener Phil Jaques toldย SEN.

"His fingers are clearly under the ball."

The confusion from the third umpire's decision comes just days after Marnus Labuschagne survived a similar review after edging the ball to South African slips fielder Simon Harmer.