Devon Conway scored a half-century to guide New Zealand to a seven-run victory over South Africa in a rain-affected World Cup warm-up game on Monday.

Chasing 322 for victory, South Africa were 211 for four with 13 overs left when the rain came, leaving them stranded at seven runs behind the Duckworth-Lewis (DL) par score.

New Zealand, the 2019 runners-up, won the toss and opted to bat at the Greenfield International Stadium in Thiruvananthapuram, with opener Conway hitting a 73-ball 78 to lay the platform for the Blackcaps.

Captain Kane Williamson, who has been ruled out of Thursday's tournament opener against England to give him more time to complete his rehabilitation from knee surgery, also contributed 37 runs.

Conway and Williamson then left the field retired hurt, but both retirements appeared to be precautionary. Lungi Ngidi and Marco Jansen picked up three wickets apiece as New Zealand ended on 321-6.

In the chase, Quinton de Kock was the cornerstone of South Africa's innings and was involved in significant partnerships with Rassie van der Dussen (51) and Heinrich Klaasen (39).

With De Kock looking sharp and still batting on 84 not out when the match was interrupted, South Africa will likely feel aggrieved at the outcome. The Proteas face Sri Lanka in their World Cup opener on Saturday.