PAARL – Heinrich Klaasen smashed an unbeaten century as South Africa claimed a 74-run victory over Australia in their first one-dayer played on a slow Boland Park wicket on Saturday.After winning the toss, South Africa overcame an early wobble to post 291 for seven in their 50 overs, a total boosted by the maiden ODI ton from middle-order batsman Klaasen, who crashed 123 from 114 balls.Australia were up with the run-rate for much of their reply, but South Africa then strangled the scoring with intelligent use of the slow pitch as the visitors slumped to 217 all out from 45.1 overs.The second match in the series will be played in Bloemfontein on Wednesday, before the finale in Potchefstroom next Saturday.The home side were in early trouble after opener Janneman Malan became the first debutant in ODI history to be dismissed with the first ball of a match.He was undone by an in-swinging yorker from seamer Mitchell Starc (2-59) as South Africa limped to 48 for three, before Klaasen and another debutant, Kyle Verreynne (48) put on 78 for the fourth wicket to steady the innings.But it was the 149-run stand for the fifth with David Miller (64) that pushed South Africa to their above par total, with Klaasen brutal on any balls that strayed in length or line, and inventive in his shot selection.Australia looked in control of their reply until the 35th over when they lost their anchor Steve Smith (76) as he fell leg before wicket to Anrich Nortje (2-39).South African-born Marnus Labuschagne (41) also impressed, but as the scoring rate slowed, he holed out to long off.Lungi Ngidi was the pick of the home bowlers as he returned figures of 3-30, capturing the key wickets of Aaron Finch (10) and David Warner (25) up front.