Marnus Labuschagne and Usman Khawaja scored half-centuries as Australia made the best of a rainy opening day to reach 147 for two at stumps in the third Test against a frustrated South Africa on Wednesday.

Opener Khawaja was batting on 54 and Steve Smith was yet to face a ball when rain halted play midway through the final session at the Sydney Cricket Ground.

The match is a dead rubber after Australia sealed the series with wins in Melbourne and Brisbane, but Pat Cummins’s side can book their place in the World Test Championship final with another victory.

Anrich Nortje took both the wickets. Labuschagne was reprieved on 70 after nicking Marco Jansen to Simon Harmer at first slip, the spinner claiming a low catch that was cancelled out by the third umpire despite replays appearing inconclusive at best.

Brief scores: Australia 147/2 (Usman Khawaja 54 batting, Marnus Labuschagne 79).