London, June 11 -- A fiery opening spell by Kagiso Rabada set the tone for South Africa, who ended the first session of day one during the ICC World Test Championship (WTC) final against Australia with four early wickets at Lord's on Wednesday.

At the end of the first session, Australia was 67/4, with Steve Smith (26*) unbeaten.

After South Africa opted to bowl first, openers Usman Khawaja and Marnus Labuschagne struggled against the movement generated by Proteas quicks Kagiso Rabada and Marco Jansen, and the ball beat their bats plenty of times.

In the seventh over, Rabada dealt Aussies a huge blow as Khawaja, the team's top run-getter in this WTC cycle, perished for a 20-ball duck. A thick edge off his bat went into the hands of Davi...