England head into the second ODI with South Africa holding a 1-0 lead after Moeen Ali played a crucial role with the ball as his side won a high-scoring opening match in Bloemfontein under the Duckworth-Lewis Method.
The Worcestershire all-rounder dismissed Faf Du Plessis, AB De Villiers and Rilee Rossouw and ended with figures of 3-43 from six overs.
When the rain arrived, South Africa had reached 250-5 off 33.3 overs in reply to England's mammoth 399-9 off 50 overs and the host nation went dwn by 39 runs.
Moeen thought he had dismissed Du Plessis in his first over on 50 when he was adjudged lbw only for a review to show the ball missing the leg stump.
But Du Plessis added only five more runs before he lofted Moeen into the hands of Alex Hales on the mid wicket boundary to give England their second breakthrough at 121-2 in the 16th over.
Moeen then accounted for the prized wicket of De Villiers (8) although it needed a stunning catch by Ben Stokes, one handed over his shoulder running across from long on, to dismiss the new Proteas Test captain.
Wicket number three for Moeen came when Rossouw (19) toe ended a catch to David Willey at long off.
South Africa were then on 245-5 and their hopes rested on Quinton De Kock – 138 not out off 96 balls – but only five more runs were added before the heavens opened.
Jos Buttler had hit a stunning 105 off 76 balls for England and there were also half centuries for Hales, Joe Root and Stokes.
Moeen, batting at number seven, made a quickfire 19 off 15 deliveries.