The rand was more than 1pc weaker at 14.60 per dollar after the figures showing growth nosedived 3.2pc in January-March compared with the previous three months.
Economists had only expected a 1.7pc contraction.
Year-on-year growth in Africa's most industrialised economy was zero compared with forecasts for growth of 0.7pc.
Bonds also weakened, with the yield on the benchmark 10-year issue up 4 basis points at 8.45pc following the data release.