Benoni - Temba Bavuma made a century on his one-day international debut to set up South Africa's 354-5 against Ireland in their one-off game on Sunday.
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Normally a middle-order batsman, Bavuma was selected as an opener for his first ODI and responded with 113, sharing a 159-run opening stand with Quinton de Kock (82).
South Africa pounced on Ireland's decision to put the home team in to bat at Willowmoore Park.
JP Duminy added 52 not out and Farhaan Behardien made 50 from 22 balls with three sixes before being caught on the boundary last ball of the innings.
Ireland's bowlers struggled against the top-tier opposition. Craig Young had the best figures with 3-81.
The Proteas are warming up for a five-game ODI series against Australia.
South Africa 354-5 in 50 overs (Temba Bavuma 113, Quinton de Kock 82; Craig Young 3-81).
Faf du Plessis (captain), Quinton de Kock, Temba Bavuma, JP Duminy, David Miller, Farhaan Behardien, Wayne Parnell, Dwaine Pretorius, Andile Phehlukwayo, Kagiso Rabada, Aaron Phangiso
William Porterfield (captain), Gary Wilson, Sean Terry, Stuart Poynter, John Anderson, Paul Stirling, Kevin O'Brien, Tim Murtagh, George Dockrell, Craig Young, Peter Chase