Sri Lanka were bowled out for just 42 runs in 13.5 overs against South Africa in Durban, marking their lowest Test total ever.
Marco Jansen delivered career-best figures of 7-13, while Gerald Coetzee and Kagiso Rabada claimed the remaining wickets.
The collapse, the second-shortest innings in men’s Test history at 83 balls, left Sri Lanka trailing South Africa, who ended day two at 132-3 with a lead of 281 runs.
Sri Lanka, third in the World Test Championship standings, faces a daunting challenge to secure a place in the final, requiring victories in all upcoming matches against South Africa and Australia. South Africa, currently fifth, remains in contention with a similar path to the final.